We stayed in Gumbet (near Bodrum) at the end of last year and really enjoyed it, although Bodrum is a nicer resort than the party town of Gumbet. To be honest, we didn't find the resorts much different from the typical European resort in terms of the types of bars and restaurants.
Definitely try and get to a Turkish bath, we found one for 11Euro each, so price around, and make sure you go early on in the holiday as the exfoliation will prepare you for a tan!
Also, they accept both their own currency (Lira) and Euro, but they seem to prefer Euro. Keep an eye on price lists as we noticed that sometimes no currency is stated so you assume it's Lira, to get a shock when you get the bill and it was in Euro!
As for the Visa, that's pretty standard, £10 when entering the country, however you can pay with a £20 if there are two of you going, they accept both £10 and £20.