This one is personal to me since I enjoy trading stocks.
One of the best books I read on the subject is "How To Make Money In Stocks" by William J. O'Neil.
I also study stock chart patterns. Google it. I will try to add some sites/examples too.
Personally, I am a member of Falcon Stocks. They help me find some up-n-coming gems.
Below are some great tips and suggestions to help you.
I invite other members to add their input as well!
PS: If your co-workers are giving you stock tips, it usually means you are the last person to know about a recent stock run or hype. Unfortunately, the last person typically gets in on the last hurrah and gets hammered all the way down (since there are no more suckers buyers after you). You're buying in while everyone else is taking profits and getting out.