Bike recommendations?

[Sooper8]

Long time bike rider but never ridden a MTB.

Had a go on a friends the other week- good fun. He has disc breaks and I fell off twice...

I want to buy second hand and not break the bank.

So- what names to look for?- what should I be checking for? How do you size one up?

Just looking for a rough starting place to begin my search...

Thanks in adavnce

[Si]

All the mid entry level bikes from the big brands will give you a good bike (if it has been looked after). Trek, Spesh, Giant, etc

Sizing - you want plenty of clearance when you stand over the cross bar....3 inches at the very very least. And you want a more sitting up position than a road bike (so that you don't get pitched over the bars when you go down a steep hill). Not your total sit up and beg town bike, but something akin to fairly upright tourer.