Do not trust people! Checkout for some good reasoning.
This thread has some solid security protocols.
Don't make threads or posts solely for putting up referral links, that's what signatures are for.
Be careful with PayPal, deepceleron's thread does a good job explaining why PayPal is bad to use when exchanging bitcoins.
Want to know what wallets are out there? Checkout Bitcoin Wallets - Which, what, why?.
Want to know how to create a really secure wallet? Checkout this thread for a good guide.
There's a lot of weird terminology, this thread is a good guide.
Are you looking to earn some Bitcoins? Checkout How to earn Bitcoins - Part 1.
If you're looking for free bitcoin giveaways, checkout the games and rounds subforum. WARNING: It does contain gambling as well. Altcoin giveaways are not allowed! Checkout this thread for more information Giveaway threads are not allowed
A warning about Alt-Coins: Almost all of the alt-coins out there are going to be a waste of time. They're being created to take advantage of people who get super excited about different things and then get pumped and dumped.
Be careful about wasting time with too many alt coins. Be careful about downloading files, seems like there's plenty of wallet stealers around hidden as alt coin miners.
You can find more good information in this post, and you should also read this thread: Beware of Increasingly Sophisticated Malware Infection Attempts