Questions about juicing

Okay, I am very new to this and I am trying to read everything I can find on juicing before I try it. My first question is what exactly is chlorella and where can I get it? Also, about how much fruits/veggies does it take to get an 8 ounce serving of juice? I know that it will greatly vary depending on what you are juicing, but lets say carrots? I just can't imagine getting very much juice out of one carrot, so how many would it take? I am also trying to get a good juicer, but I am hearing conflicting stories on which ones are good. I have heard good things about the Jack Lalanne juicer, but how good can it really be for $100? Surely to get a quality juicer I will have to spend several hundred right? Any recommendations? What are some "must haves" on a juice fast? What I mean by must haves is what kinds of veggies and fruits should you include to make sure you are getting proper nourishment? How much weight does a person generally lose on say a 30 day fast? I wouldn't mind losing about 10-15 lbs, but I absolutely do not want to lose anymore than that. So should I just make sure I take in a lot of calories? Thanks for any input you might have! :-)