If you're using the 18F series PICs, I would HIGHLY suggest you try the official microchip C compiler for them, C18. the hi-tech C compiler mentioned in the previous post costs $950 for the full version, for example, and apparently only offers a 28-day time-limited demo version.
Microchip's C18 compiler has a FREE student edition that is almost a full version: the only limitations are a few reduced optimizations, and not supporting the 18F extended instruction mode. Neither of those should be any problem for a hobbyist. And, for the first 60 days it is a completely full version.
But, you could probably use the tutorials intended for the hi-tech C compiler as a starting point, and (probably) modify the syntax a bit to get it working with a different compiler.
Are you already familiar with C programming in general, and with PIC programming in assembly or some other language? if so, you can probably learn what you need by just looking at C18 example code. if not, you had probably better get somewhat familiar with C and/or PIC programming (ie - in assembly) before you try messing with them together, as it's an added level of complexity.