I guess the title says it all- I want to know how to make a bow. I imagine it is alot harder than making a sling or a blowgun. I don't have any lumber or anything, so I will need instructions from scratch. The best thing I have to cut with is an old swiss army knife, so I might need some advice with that as well.

best to find a book or ask around reenactment groups to meet there bowyer i did that and he helped me make a yew longbow

There are several threads on bow making and knives here, waiting for you to read them.
Just type in the word bow (or knive) into the search function of this site and specify the days. I find it most usefull to search in blocks of 50 or hunderd days with a subject like these.
You need to look in other primitive weapons (only).

But I am sure there will be someone out here giving you a helpfull answer again.

Willeke

For a bow.

List.
Coarse rasp, knife (good one), file, plane, sandpaper of various grade, camp hatchets are dandy for workin wood quick, some basic dimensions of a bow, linen-hemp-nettle fiber-silk-b50dacron-sinew for string. Also a decent stave of wood, straight grain, no knots, at least three inches wide, six feet tall, two inches thick. Boards also work- 2by1by6. Woods- red oak, white oak, ash, hickory, rock maple, hackberry, elm, walnut..
Mark out your dimensions, leave the handle beefy , hack with axe until reasonable close, then plane the edges. Make certain the cross-section is rectangular. About two inches wide until the last eight inches, where it tapers to 1/2". Make the handle 1 1/2 " wide, thick as is comfortable. When the handle narrows, it should also get deep, make sure the fades  "overlap" the handle tapering, then it wont bend prematurely. Make it about 3/4" thick. Then cut nocks. Make sure to plane everything smooth. Test it weight, make sure everything bends smoothly. If something bends too much, dont bend it again, rasp wood off everywhere else. A few hairs of thickness is the difference between 50# and 70#. Be slow and steady. It isnt a rat race. Then put it on a scale (on tillering tree), test weight. NEVER BEND IT PAST YOUR EXPECTED DRAW WEIGHT!. It should bend about ?# at twenty eight inches when you are done. Then shoot the heck out of it. Have lots of fun.

My second bow was great untill you got half way up. then there is about 4 knots one right after the other  :)

If you want to make one out of a sapling you might want to try this plan:
http://www.aircav.net/survival/asch12/fig12-6.gif
That looks like it would have a very strong draw weight! I would thin it down a bit.

Go to www.primitiveways.com to get info on a sapling bow. I have gotten 2" diameter saplins, for a really deep handle, you might want to take a saw, and cut the 4 inches from the middle, two inches off direct center. Then split it. I have used that for deep, comfortable handles. Doesnt bother me any. Kindof nice.

Traditional Bowyers Bible volume one. Buy it.  $16 at amazon
Also                 http://p081.ezboard.com/fpaleoplanet69529frm13
Its a forum for primitive skills. If the link doesn't work just type "paleoplanet" in to a google search.