Stiknruda - The best place to get info on the written exams is to get some brochures from the various schools e.g. Oxford, PPSC, Bristol etc. Most are only doing the JAA ATPL written exams as they haven't got round to doing any CPL courses yet, but I think that Oxford and PPSC do the CPL ones as well.
You can either do a full time course studying for the exams or do whats known as a distance learning course - they send you all the books, you read them then go down for a brush up course before you sit the exams.
The CPL module covers a minimum of 5 hours general handling, 10 hours visual navigation and 10 hours instrument flying. 5 hours of the course and the test must be done in a complex aircraft i.e. 4 seats, variable pitch propellor and retractable undercarriage. You can use a twin-engined aircraft.
Costs for the course are roughly:
£3500 for distance learning course
£4500 for the CPL module
£4800 for the FI course
Hope this helps - feel free to ask for more info.