I don't think there is a clear answer here, you have to do what makes you feel good.
I am no expert, something of an amateur myself, but look at my work:
http://www.flickr.com/photos/rmthompson
All of my stuff is shot with available light, (with a point and shoot Canon A610 no less) with the exception of the model on the first page! No I didn't use a strobe or big expensive lighting kits... I used a Wal Mart floor lamp with three bulbs.
So get yourself one of these:
And learn on it before you get the expensive equipment. I personally like using the "REVEAL" bran bulbs, as they give off a more natural light, and get the brightest you can get.
Then on the other side of your subject, instead of getting and expensive secondary light, get one of these in the automotive section of Wal mart:
(not the car, the sun shade!)
It bounces light well, and will eliminate SOME of the harsh shadows.
Oh and if you want to use a nifty background like I did, get a cheap 5 dollar black sheet...
Later on you can go out and get all the professional equipment that does this, but for now, do what you can, expirement.
Someone told me that if you learn how to take the shots you want WITHOUT all the equipment first, it makes you that much better of a photograher.
Cheers!