Evenin chaps and ladies

I'm in the process of fixing up a room and everything is done. Except the
carpetting. I got a quote today from carpet right for carpet and fitting etc
and the guy said I can save some money putting the grippers down and the
underlay. The underlay they sell is £4.99 a SQ metre!!! and the carpet
runners are about £2/19 a sq metre so I popped into B&Q who sell packs of
carpet runners cheaper and underlay I think it was £45 for 6.1m of green
medium underlay which shall do.

I have never fitted carpet runners or underlay and wanted some advice.

The floor its going on has hardboard down. How far from the wall does the
gripper need to be pinned down ? also when you get the the corner or the
length your working on how do you set the grippers up does it just have to
butt up next to the one already laid or ... ?

Also I need to carpet the stairs, where would I mount the grippers on stairs
?

I'd appreciate any advice, as I'm on a tight budget to be honest and this is
my weekend to do it all ... I have just discovered which way round the
hammer goes

Thanks kindly all.