DipTrace is the most intuitive of the "professional" design packages IMHO (but I haven't tried AutoTrax), the free version will see you well into getting into some moderately big hobby stuff, and the paid versions are reasonably priced.
As for board houses, don't know about in the UK, but there are plenty of cheap manufacturers in China for prototypes, usually in quantities of 10 boards for a buck of two each.
For example, dirtypcbs.com protopack gets you "around" 10 5x5cm boards, sometimes as few as 8 sometimes as many as 12, with free shipping, for $14 USD, in a number of colours.
Of course, you have to not mind waiting a few weeks for shipping, or pay extra for faster shipping :-)