I have built Lakeview manor, didn't choose the bedrooms option but have built extra beds upstairs. I read that this would allow me to adopt but it keeps telling me I have no room?

You must buy the children bedrooms.

I believe you have to furnish the room with other various furniture as well as beds to allow the adoption facility.

http://elderscrolls.wikia.com/wiki/Adoption

Cool thanks, don't think I have a chest in there so that's probably it.

May put if off for a while, just blacked out in whiterun after drinking with a stranger and ended up in Markarth so maybe I'm not the most responsible of parents!!

Yes, not the ideal role model LOL!