What browser do you use? I recommend firefox because there are many extensions that you can install to increase the security of your browsing including mcafee site advisor.
I also suggest you download and install a program called spywareblaster. it blacklists a lot of unsecure sites so that they won't even load in your browser.
there are many more things you can do to increase your security online, but I don't want to flood you with too much stuff at once, say if your want more advice.