Where do you get phone numbers from?

I am new to PBX and would like to start a hosted PBX service. I’m not not too worried about the installation of asterix on a linux server. My only concern is phone numbers. Where do you buy phone numbers from? I would like European numbers, mainly for Spain and the UK. Can someone point me in the right direction?

Many thanks in advance.

a good point to start is: http://www.voip-info.org there you can find many links what you are looking for, we using http://www.didww.com, http://www.didx.org/ and http://www.voxbone.com/ all working with IAX and SIP, we have on our website http://www.astertools.com/tutorials a step by step instruction for installing a Linux debian system with Asterisk, following this instructions you can be up and running in 1 hour.

good luck for your business