I've studied at Stanton School of English, the staff is competent, very heplful and very friendly, there's no problem with coursebooks or access to the photocopier.
On the downside, there are only three computers for CELTA students, so it's a good idea to bring your laptop if you want to write your lesson plans or assignments during a lunch break - and you WILL want to spend every spare minute of the third week of intensive course writing your plans and assignments. Also, there's only one copy of each of theory books (Learner English, The Practice of English Language Teaching etc.) - so you'll probably want to buy them or download .pdf versions (legally available in online libraries and easy to find through google).
You might be teaching a large group of students (up to 22), but there are also small groups (of about 8 students).
Generally speaking, they provide you with necessary resources and facilities, but the main advantage of this school are GREAT tutors. I think it's a good choice, I would advise this school to anyone. :)