Hi there
The hammock is just the start.. once you start to look into this and get the bug.. and you will!!!
You'll need a few items more than just the hammock. I found DD hammocks did a good affordable range of gear that let me get started for the first time this year..
I'd recommend if you go down this route you look at their Frontline of Travel hammocks.
You'll also need a tarp, I've got both the OD & Camo, but find the OD better made as the guy points are all reinforced.
You'll need some form on under insulation... I used an self inflating mat for most of the summer and it was just fine... but finally cracked and got the Snugpak underquilt recently...
You'll need a reasonable sleeping bag. I find the best way is to use it as a quilt, unzipped. A centre zipping military style bag makes this easier. It is hard and very tight to actually get into most bags while in a hammock. I found I just tied myself in knots. Using the bag as a quilt prevented this and with the under quilt I was very warm. I've sen on the hammock forums a lot of guys adapt a US army poncho liner as an underquilt. These are a pretty cheap alternative.
Happy Hanging
Cheers
Gareth