Newbie needs your opinion... which bike?

Start well: Fuji track at £350. Need to add a brake though.
http://biddlebikes.co.uk/catalog/index.php?cPath=342&osCsid=3b9a7b97528246006409e9ce769a4581
I would not use shops to buy unless you want something so exotic that there is no other way. By all means use them to look and try. The mark up in shops is way more than justified, and even with postage added the comparison with on line is unfavourable. Also check out Wiggle and Ribble, or once you have decided, Google the marque and find the cheapest supplier.

though you're right, what about the prisoner's dilemma? If everyone bought online, all shops would go out of business, at which point, there would be nowhere to try bikes out before you bought. Then some entrepeneur would open a business selling bikes in person, and call it a bike shop. Where would it end?!