How do you use Steam Gifts? (Join groups, white lists, etc)

Well, if you are looking to join groups there are plenty public ones on steam, however most of the better groups are invite only and have recruiting threads in the "groups recruitment" category, apart from that, making GAs will increase your level and thus allowing you to enter for more games and at better odds :)

Welcome!
Just let it flow and lurk the forums. You'll find your path.

I like your avatar =))

There are some public ones, but they don't tend to give the "best" giveaways. You'll get a nice game every once in a while, but they tend to have a higher member count, and people don't feel the groups are part of some community (sometimes there are public groups affiliated with private ones that get some giveaways, Golden 100 has one that gets a lot of GAs when they have their events.

The best way to get accepted into groups is to make yourself known. Positing on the forum and being active in general will make people take notice of you (just make sure that they notice you in a good way ;) ). Hosting giveaways is a good way to get noticed, showing that you're not here to leech, and you don't have to break the bank either, doing events for your bundle keys will get you on whitelists and get you into whitelist groups.

Just remember that, as with most online communities, people have a short memory. Unless you do something really noticeable, you need to keep things up.

Edit also, unless you make a lot of public giveaways, your odds of getting noticed are better if you post private forum giveaways and make threads about it.

Thankyou everyone for suggestions. They are really helping!

Give away lots of games, be active in the forums, and be nice to people.
Then you'll end up on white-lists and you'll get invites to giveaway groups. :X