I'm in the same spot as you, so let me tell you my experience. I'm just learning (currently 3 lessons courtesy of my husband who owns a Honda Interceptor), and I'm signed up for a Motorcycle Saftey Course at the end of May. I have my learners permit, but have never ridden before.
I first bought a Honda Shadow VLX600 about 3 weeks ago because it was gorgeous and looked like the HD Sportster for half the price. The Honda Shadow is a cruiser, and for me @ 5'4", 140 lbs, found it to be really top heavy. It was harder for a beginner like me to maneuver around tight corners - especially taking off out of them like in parking lots. I came to a quick stop during my 3rd practice, and tipped over because the front end flopped left, and rolled out from under me. I of course jumped back up and got right back on, but it taught me a most valueable lesson - never buy a bike by it's looks only. Sit on it, tip it, roll it, ride the parking lot, but buy a bike that fits you. You'll be a lot safer.
I promptly took the bike back and bought a Buell Blast instead. It's not a crotch rocket for sure, but the front wheel rake isn't as steep as a cruiser. The handle bar length is somewhere between a cruiser and a crotch rocket and is a very comfortable reach for me. It's 100 lbs lighter than the Honda, and the front end is very stable. I can take corners with no problem. It's also the bike they use for several training classes in my area. The clutch isn't as forgiving as the Honda, but I'll get used to it as I would any other. Only downside for me so far is that it rattles quite a bit on idle.
I may outgrow it at some point, but I can see that it will help me to build my confidence. It does highway speeds and will be a great leisure bike until I grow out of it...if I ever do.
Price - I found the 2005 Honda Shadow with 73 miles on it for $4700 (someone bought it and returned it), and bought the 2003 Buell Blast with 8 miles on it for $2600 (it had never sold off the showroom floor). Check with several of your local dealers for bargains like this. They won't be out on the sales floor, but if you ask, they'll take you to the goodies in the back! Good luck and safe riding!