Os x tiger question

I'm going to be reinstalling tiger on my friends Mac but he doesn't have the disc how do I obtain a copy

eBay, Craig's list, your local Green Sheet, etc.

What is the local green sheet

The local Green Sheet is an advertising newspaper that's distributed in many cities and towns. Ads placed in there can run for an entire week and are usually less expensive than a newspaper ad. The Green Sheet is free and can be found at the entrance to supermarkets, Wal-Mart, Target, etc. And yes, it's colored green.

So I've searched but nothing I did find files online but I don't know what ones to go with one says ppc one says intel what's the difference

Which Mac do you have? Year and model? If you have a Mac model prior to 2006 it's likely a PPC machine in which case you would need to purchase the PPC version of Tiger.

All I know is that it has os x tiger 10.4.11 that's it so if I download a copy I know there's a ppc and intel version if I try one and it doesn't install it's the other one so I think that's what I'm going to do so my next question is how do I burn a .dmg file on windows

First, there are no legal Tiger downloads. Tiger is only available on disk - either the PPC or Intel versions. Windows does not do dmg files, only iso.