I have a ton of stickers, and I can't really add them to my own sticker collection. Am I allowed to make a post to give stickers to anyone that asks? If so, what section would that go under?

You can do that in Advertising, Subforum Giveaways. :)

There are several sticker sticking threads in the general discussion and user based games or you can ask your friends to stick you. All are acceptable. c:

You can also do the aforementioned giveaway thread, if you really want.

Additionally, if you would actually like to have your stickers placed into your album, there are a couple of threads in the Achievements Forum which may appeal to you:

[topic not found] for help with batch sticking. Users create trades, list their lots, and ask for help. It's can be a bit of a risk, I guess, but most people I've run across in there are really helpful and honest.

If you just want to casually fling stickers back and forth with people, there's [topic not found], too. [edit] ... and totally beat me by the eight minutes I spent triple-checking myself. Rofl ah well...