If you want to join bounty campaigns, look no further because bitcointalk has a thread specific for bounty campaigns. Check this link: https://bitcointalk.org/index.php?board=238.0. There are many bounty campaigns there that would cater to your needs. For your information, signature campaigns I think provides the best rewards based on tasks. But you have to wait until your get junior rank before you can join. With stakes increasing as your rank go up. If you are good in words or journalistically inclined, translation and content campaign also provide hi-stakes. But for newbies, you must content yourself with social media campaigns first. But don't expect big rewards from it as there are so many participants in this campaign.