Have you tried laying out the UV's for a simple, six-sided cube? It may be incredibly boring and basic, but it gives you the general idea behind UV layout. If you have a "complex" creation, I'm afraid there's no easy way to learn it other than to dive on in and take a stab at it, keeping in mind what you know from laying out UV's on a cube. I say "complex," because complex can be as simple as a 3,000 poly game-res character!

Applying a checker texture can help vastly when laying out UV's.

I'm off to browse for UV layout tuts...