I'm doing the Brighton half-marathon end of Feb and I'm not that fazed. Its part of my training for the full Brighton Marathon in April.
I've lost about 2 weeks training due to the weather so I just figure it might take me a bit longer and hurt a bit more than I would have liked.
Really looking forward to it in a weird kind of way cos when I started running about 3 months ago it hurt like hell but I'm over that now.
Defo go for it.
Regarding training tips I think the Runners World website is pretty good. I'm also using the New York Marathon Training Guide which is excellent.
Bottom line is you need to be running at least 3 times a week, plus some cycling. Start slowly and build progressively to avoid injuries and include some interval and fast pace stuff. Do as much off road training as you can to preserve your joints.