Affiliate Marketing?

So, Another project starting..... Has anyone heard about affiliate marketing? What do you know? is it really worth while? See, i know that it takes time and patience and targeting the right people in your site. There are so many things to advertize! See my blog is about a little bit of everything, product reviews for bzzagent, my own 2cents in everything i do on line, and earning money... so how do i know what products are right for me to advertize? I NEED HELP! someone one anyone? I really hope I catch a Marketers eye here so i can get a hand :\ Hopes much? Liz