I've had a few people ask me about texturing and creating UVS for models, so I decided to make a journal for various sources that I also could expand on in the future. If you have any links you want to share I will gladly add them. Anything that has a icon next to it is part of the latest update.
The size of the map really depends on the object, I've worked with really low res maps like 16 to 256px, to medium res maps at 512px to 1024px and high res maps at 2048px. For low res maps it is wisest to start at the resolution you are going to use since every pixel counts. On everything higher it really depends, I know when you have a game being