Seeking First Road Bike Advice?

I have been doing some cycling for fun using my old mountain bike that I bought when I was 17. 3 years later  I'm looking for a decent road bike, but I can't afford something too expensive.

I'd be grateful if anyone could tell me things I should be looking out for, makes etc and the best place to pick one up. Is second hand an option?

Thanks.

What are you going to be doing on it ?

Buying second hand is a option but size is critical, a trip to your Local Bike shop is a good way to start, most shops are happy to give advice, just make sure you give them some business in return.

Yes, what's it for, what is the budget.    Not sure what bikes with say Shimano Sora and carbon forks start at now - £500 plus maybe ?

As a novice if you have that kind of money to spend and nobody local to advise you maybe buy new, if it's less then second hand may be worth a punt, but as Dave says the size is crucial.   

Cycling to and from work 6 days a week. It's around a 15 mile round trip into the city and back. Long rides for weekends on country roads. Nothing too serious. I want to build things up before maybe doing a triathlon in a year or so.

I have around £500 to play with at the moment. Looking to save more if I find a particularly good bike.

My pays a bit shit and I don't have much of a student loan to speak of.

I was really naughty and went to the big local bike shop and got measured up against a few brands, asked them a billion questions about what i should be looking for and then went shopping on ebay for a second hand one. I have since been back and purchased bits and bobs from them, promise  

I wasnt in the market to spend £1500 on a new bike that i was blatantly going to trash, while i learnt how to ride it (first outing into road bikes). I waited quite a bit for the right thing to come up on ebay (set myself a £500 budget & a 105 groupset minimum). all the cannondales/scotts etc were going for silly money and a barely used Litespeed Vela with 105 groupset/carbon forks/carbon seat stays came up, watched it for 7 days, all mine for £350, well happy.

I am really happy i didnt spend loony £££ first time out, as i have fallen off him (freddie) numerous times (mainly at first because i kept forgetting i was clipped in). Also because i spent less, i'm not massively precious about wanging him around corners/going out in the rain etc!  edited to add that - i love him to bits and if he was pinched/written off i would be devestated!