Iam keen to start the procss of applying as a skilled worker for immigration to Canada, but want to do this at the right time. I would not want to move immidiately if approved? I havea house to sell, etc. So:
No problems, man. You are not the only one in this situation. Just Land, activate your permanent residency and come back and start preparing again to go after you've sold everything you need to sell.
Why don't you start from here and do some home work yourself.
http://www.cic.gc.ca/english/immigrate/skilled/index.asp
How long does the process take approx from a UK aplication?
Here, help yourself:
http://www.canadainternational.gc.ca/united_kingdom-royaume_uni/visas/processing-traitement.aspx
If appoved, how long do I have to actually move to Canada?
Once you are approved and have been issued the Visa, you have till the validity of your Medicals, Your Visa and your passport to land and activate your permanent residency.
Here, help yourself:
http://www.cic.gc.ca/english/immigrate/skilled/arriving.asp
I am sure others will have a lot more to add to the above.
BobbyB