I have just been in Europe for 2 weeks and I used booking.com to book most hotels. It has lots of choices from very cheap to very luxury. Also provide very detail and useful info. including transportation means. Normally they don't charge you (unless no show). Just pay to the hotel counter is good enough.
Yep booking.com is a very good and reliable site, sometimes with 4 star hotel rooms at a very low price! I used that alot last year, along with hostelworld.com
Yes you'll need a credit card to pay 10% deposit for the room, then fix up the bill when you arrive.
Good luck!