What cities, Julesmac?
And an approximate daily budget might help others to give appropriate suggestions?
I use a variety of sites, for hotels, apartments and occasionally B&Bs.
Always check as many references and reviews as possible before booking.
It's very much a personal choice, though, and depends on priorities and preferences, so the more information you can provide, the more relevant and tailored the suggestions can be.
Best of luck. The choice of accommodation can make a world of difference to the travel adventure.