I use the uni knot, almost exclusively. It can be used to tie two lines together, to tie a hook or lure to the end of your line, or to tie a loop in the end of your line. I have never had a falure with this knot, and you can fish your whole life without knowing how to tie another knot. The only other knot I use is an overhand loop, if I want a loop on the end of my line. Here are a couple of sites that illustrate how to tie this knot.
http://www.in-fisherman.com/magazine/guides/cg2003Sp_Uniknot/
http://www.killroys.com/knots/duncan.htm
Animated:
http://www.animatedknots.com/uniknot/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com
As far as fishing strategy. Use live bait that you find locally, like worms, crickets, frogs, crawfish.
A lot depends on what species of fish you are after, but if you are on a lake, your best bet is to be patiant and bobber fish with sinking bait like a worm, or sinker fish with floating bait, like powerbait, or marshmellows.
If on a river or creek, or body of water with a currant, target slower moving water, like the bend of a curve, the bottom of a pool, behind large rocks or fallen tree trunks, etc.
Trout seem to be open water fish, and can usually be caught in many different areas of a lake from open water to cover near shore, top of the water, to way down deep near the bottom. Most other species though, such as bass, bluegills, and crappy are usually found near cover. Underwater bushes, trees, rock piles, points, etc. are good places to target.
As mentioned before, live bait is best, but if it's hard to come by or if you just aren't catching anything, you can use lures if you have them, or if you don't, just about anything shiny will work: earings, wedding rings, aluminum foil, etc. Think of shiny objects as small fish/minnow immitations, and should be fished in a way that gives them movement. While it may work, it will not be the most effect way of using these items if they just suspend in the middle of the water, or just sit on the bottom of the lake.
I hope that kinda gives you an idea, it's hard to teach someone fishing without taking them fishing. A lot of fishing knowledge comes from just plain experience and is hard to teach someone. When you have literally fished your whole life, some things are just instictual, like you just know there is fish there, you may not be able to explain why, but you just know they are there. Or, sometimes you just know which color or lure will work at this specific lake or river, because you know that particular body of water. Sometimes, what knocks 'm dead at one lake, won't even get you a bite at another lake.
Like I said, I hope this helps, but the best teacher is experience, and I advise you to go fishing if you want to learn how. NOt only is it a good survival skill to have, but you will find that it is one of the most enjoyable past times that there is.
