Re: PowerPC
Actually this is not a very relevant forum for your question. Anyway i'll try to contribute what i know.
PowerPC is a CPU structure joint developed by apple, IBM and motorola.
Like echo47 said, an Apple MAC is powered by powerpc. For embedded system, IBM and motorola(powerquicc, powerquiccII) are widely used in communication industry. To start you can get a eval board and play with it(There are plenty of them in the market). The most popular free compiler is gcc. Normally the vendor of eval board will give u all these cross tools.
The instruction set for PowerPC is free from IBM/Motorola web site. C programming has nothing to with that. Your compiler will take care the translation.
regards