It seems that every drawing class requires a whole new list of things that you should get. Do not run out and buy everything on this list. This just gets expensive. I think it is better to get more experience using the mediums you enjoy the most. You can do a lot with just a pencil. Consider this list as suggestions and thoughts about different items that you can bring with you rather than a required shopping list. There are three guidelines to keep in mind when selecting field equipment: simple, light, and portable. Hold all your materials to this standard. Everyone has favorite tools so customize this list to meet your needs. My favorite items or essentials are in bold and my watercolor preferences underlined. You can get many good and inexpensive art supplies online from Daniel Smith art supplies.

• Sketchbook or drawing pad: There are two good ways to go on this, either a bound hardcover sketchbook or a Komtrak Inspiral notebook with removable pages.

Hardcover sketchbooks with sewn in bindings will protect your work and stands up to field conditions.  You may need to reinforce the binding with duct tape as the book gets older.  I avoid the spiral bound books because the pages are able to rub against each other and smear your pencil work.  My favorite is the Canson Basic Sketch Book 8.5" X11".  It is acid free with 65 lb. paper and cost around $8.00.  It has a hard black cover and sewn in pages.  The paper has decent texture for pencil work and will accept a little watercolor (although you will have to live with some buckling of the paper and will not be able to do much lifting out).  There are other brands of look alike sketchbooks but the smoother, whiter paper will immediately absorb watercolor, making it difficult to make a decent wash and the color bleeds through to the next page.

The Komtrak Inspiral Notebook allows you to remove clasps at either end of the binding, remove the spiral binding, and insert or remove punched pages as you wish.  You can buy pre punched pages from Komtrak.  I like the Arches "en-tout-cas" watercolor paper (smooth hot press texture on one side and rough cold press surface on the other) and the "premium artists' sketch paper" for general sketching.  They also have a good medium weight multi media paper that will take light watercolor washes.  You can also cut your own paper to a size you wish and get it punched at a photocopy/binding store such as Kinko's.  If you can not find Komtrak Inspiral notebooks at your local art supply store, you can call them at (516) 293-7170. Toned Paper:  You can buy a few sheets of gray or brown toned paper at an art supply store, cut them to fit your sketchbook.  You get interesting effects with watercolor, gouache, or colored pencils.  You may keep a few sheets at the back of your sketchbook and glue them in at appropriate places or get them cut and punched and added to your Inspiral notebook.  I use this notebook when I am backpacking and need to keep my sketching kit light or when I want to have a variety of paper types.

• Watercolor Postcards:  This is heavier stock paper that takes watercolor better than a sketchbook.  You can glue the cards into your book or mail them to a friend.

Drawing Tools

• 0.5 mm mechanical pencil for fast sketching
• 0.3 mm mechanical pencil for detail work
• Col-Erase non-photo blue pencil for lightly sketching in guidelines or a preliminary sketch over which you can draw with a heavier graphite pencil.
• Soft white plastic eraser such as "Pentel Clic Eraser"
• Fiber tip pen:  black/ gray, water soluble.  Try a Pilot razor point pen (creates a cool gray wash when you add water with a brush) or a fine Espresso pen (creates a warm brown wash- but be careful, the ink form this pen can bleed through some sketchbook paper).
• Fiber tip pen: waterproof.  Make sure the ink does not bleed through your paper.
• If you like soft pencils try the Design "Ebony" jet black extra smooth pencil or the Berol Prismacolor Warm Gray 90% pencil
• pencil sharpener
• protective pencil case
• A handy portable bag or soft case to hold all your sketching supplies that fits neatly into your backpack or (ideally) over your shoulder with a strap.
• medium sized plastic bag (to protect sketchbook in a downpour)
• large rubber bands (to hold sketchbook pages down in the wind)

Media for Color 

• If you like colored pencils, select your favorite colors including light gray and several muted browns and greens.  Bundle earth tones, cool purples and blues, and warm yellows and reds separately with rubber bands.  You may also be interested to try watercolor pencils.  Personally I have a lot of trouble with these because the colors change when you add the water but some people like them.  If you are not already comfortable with watercolor, go for colored pencils, they are much easier to use. The Prismacolor Verithin 36 color set is a good starter.
• If you use watercolor, find a small set of colors, portable brush, and small, tightly sealed water bottle (such as Nalgine). I use a collapsible plastic palate that I can recharge with colors from paint from tubes when I need to.  I let the paint dry for a couple of days before closing the palate and heading back out into the field. I use a 28 well folding plastic palette that is 3-=3/4" wide by 10 inches long.  It is lightweight and has five separate mixing areas (and a sixth that folds out).  This is the best palette that I have found for watercolor in the field.  You can order them through Black Horse Fine Art Supply 800-790-2552.  Ask for item number 10242000, the "3-3/4" x 8-1/4" quality folding plastic palette"- cost is $6.69 plus shipping.  They also sell a smaller 18 well pallete.  It is item # 10243000 Folding Plastic Palette 3-3/4" x 8-1/4". 
• Colors on my palate: I have underlined my top ten.  These are not necessarily the best colors.  Each artist has different preferences.   Neutral Tint, Sepia, Burnt Umber, Burnt Sienna, Indian Red, Ochre Gold, Yellow Ochre, Naples Yellow, Buff Titanium, Hooker's Green, Green Gold, Olive Green, Oxide of Chromium, Undersea Green, Prussian Green, Payne's Gray, French Ultramarine (blue), Cerulean Blue, Cobalt Blue, Moonglow, Alizarin Crimson, Quinacridone Rose, Cadmium Red , Cadmium Yellow, Quinacridone Gold, New Gamboge, Cadmium Lemon, and Hansa Yellow.  All these colors do not fit into one of wells on my palette and so are included at the edge of one of the mixing areas. I also have a dollop of Permanent White (Gouache) in a separate part of the palette so it does not mix with the watercolors.  These paints are a combination of Windsor Newton Artist's colors and Daniel Smith colors.  I really like the Daniel Smith colors and as I use up my old Windsor Newton colors I am replacing them with Daniel Smith.
• Waterbrush  If you are using watercolor or watercolor pencils, consider this terrific sketching tool.   It is a brush that holds water in the handle so you do not need to dip it into water to paint.  It takes some getting used to but it is very handy for quick sketching especially under difficult conditions.  Brushes come in several sizes.  I recommend the broad tip (18mm).  These brushes are made by several companies. The Pentel Aquash waterbrush with a fatter handle and slightly longer, stiffer bristles is by far my favorite. They are available for $6.50 at Art Essentials 1-800-736-7772, ask for the pointed Aquash Waterbursh from Pentel with the broad tip. You can also buy the Pentel brush at the Kinokuniya Stationary and Gift store in Japan Town in San Francisco ($8.92 including tax). If you use a waterbrush, carry a rag to wipe the brush clean to change colors.  I know this sounds like a gimmick but once you try it, you may never go back to traditional (and more expensive) brushes for your field work.  I now use a pentel brush almost exclusively- even for my studio work...
• White gel pen such as Pentel Milky gel Roller or Jelly Roll are useful to draw white lines over watercolor for leaf veins or hairs.  You can tint it with another coat of watercolor after it dries.

Other Equipment

• warm clothes (dress in layers)
• rain gear
• sun hat
• sunscreen
• lunch
• drinking water
• day pack
• comfortable walking shoes

Optional Equipment

• binoculars, I recommend the Pentax Papilio 8.5x21 Binoculars. They can focus on a bug on a flower a foot and a half in front of your face and are great for things that are far away as well.  The close focus feature will open up whole new worlds for you. They are inexpensive too! (I do not receive a commission for this plug).
• spotting scope
• camera (digital?)
• hand lens or small magnifying glass
• field guides
• lightweight stool or sitting pad