Welcome, im pretty new and am preparing for my first Tri in May. I would say this forum is one of the best training/advice resources and the people hare are so helpful you can get the answer to vitually anything.
I have attached a few sites that I have looked:
http://www.trisportepping.co.uk/trainadv/trainadv.html
http://www.trinewbies.com/
http://www.britishtriathlon.org/
http://www.trifuel.com/
http://www.bpr.com/try.htm
Moving from FLM to Tri should not be that difficult, ive heard that doing a Tri (Olympic Dist – 1500m swim, 40k bike, 10k run) is easier than a Marathon. You just need to work on the swimming and cycling to change events.
You need to split your training week into 5-8 sessions, e.g. 3 bike, 2 run, 2 swim. If your not a strong swimmer consider swimming lessons at the local pool as technique is the key.
If you want any advice just ask.