Depends on exactly what you want and how much you wish to pay, but Jessops do them, and they also do a design service with various sizes (the designers do the arranging for you).
You will only need photoshop to crop/spot colour/adjust light levels where necessary. It's not really about image size but about filesize (the larger the filesize, the better quality the images will be if blown up etc).
---------- Post added at 13:26 ---------- Previous post was at 13:26 ----------
There are many places that do photobooks. Even Tesco/ASDA