Big question, long answer.
There are a few guides, but they're usually pretty slim. This is because there are two levels to navigating by stars: one is fiendishly simple and therefore doesn't pack a whole lot of information. The other is complex, and requires measuring equipment I'm assuming you don't have.
First, it does matter what hemisphere you're on. And it definitely matters what latitude you're at. If you're in either hemisphere, the further you go toward the equator, the more zodiacal constellations you'll see.
1. In the North, if you start moving South, the lower and lower the North Star is in the sky. You eventually will not be able to see it. Also, be sure you know which star is Polaris: I've quizzed a few people over the years who point to a star in the Big Dipper and think that's it. It's a fairly bright star at the end of the Little Dipper (the North Celestial Pole, or NCP).
2. In the South, there's generally a huge misunderstanding about how the Southern Cross works. It does NOT point South, but points toward the Southern Celestial Pole (SCP). There is no easily recognizable star at the SCP (there's a star close to it, but it's generally too faint to be seen unless conditions are dark...in which case, it'll look like hundreds of identical stars around it).
Here are some basics to get you started.
First, determine which way is up. Stars in the Northern Hemisphere rotate counterclockwise around the NCP, but also rise and set. If you can find the NCP, note that it will move slowly from East to West... that is, in about one hour, it moves about the width of your hand. Get to know this motion, because it'll be the basis for later measurements.
As you move toward the equator, the NCP moves closer and closer to the horizon. This is good, because it gets closer and closer to the North. As this happens, Orion tends to become more visible (in the North, it tends to hug the celestial equator, and isn't too obvious until winter). Stars in Orion's belt *tend* to point East and West (not precisely, but this can get you going).
As you move further South, Orion moves way overhead, and now you start to see the Southern Cross. Here's how it actually works: take note of the position of the cross. Its long axis points to the SCP. Wait about 30 minutes and look again. Note where it points. Wait another 30 minutes and look again where it points: connect the three imaginary lines, and that's the SCP. Draw a fourth imaginary line from the SCP to the horizon, and that's South.
So here are three constellations to make sure you really, really know (remember that if there are clouds or haze, you might only have three or so stars from which you can identify the constellation with): Ursa Minor (the little dipper), Orion (useful around the equator), and Crux Australis (the southern cross).
As you get more familiar with the sky, this becomes easier... you generally get to know which constellations are "east" and "west" of where, and don't have to wait 30-60 minutes to get your bearings. For example, in the North, Cassiopeia ("W") is easy to spot, as is Leo ("?") and Ursa Major (the big dipper). Know the relative positions of these guys, and you'll always find North, East, and West.
In the South, also look for the Magellenic clouds (galaxies actually, and not constellations). These two guys form a lazy triangle with the cross around the SCP. If one's down, the other two are probably up.
In between (equatorially), Orion's belt points from right to left at Taurus, usually visible in both skies. Look for the Pleides: a spattering of bright, blue stars all clumped together. Orion always chases Taurus around the NCP.
Canis Major is easy to spot only because it's got super-bright star right at Orion's right leg. Remember that if you're below the equator, Orion tends to stand upside down.
Hope this helps. It's scratching the surface, but it's a start. Remember:
1. It isn't easy: it takes time to navigate by the stars (often 30-60 minutes to be safe and sure).
2. Nothing beats knowing the general locations of important constellations: the more familiar you are with who is to the left of whom, etc., the easier this gets.
3. Remember that stars move two ways: west to east, and around their respective poles.
