Sanding wooden floors - DIY novice!

My girlfriend and I recently purchased our first property. It is an old council house, built in the 50's and part of the attraction was that the original wooden floors have been retained. However, they are showing signs of their age and we have been thinking of sanding them down and varnishing them. They are in reasonably good condition, except for one room where there is black staining around the nails.
Has anybody undertaken this? A friend of mine thinks it would be better to hire an (industrial?) sander as opposed to buying a hand held one - is this a good idea and if so, anybody recommend a place to hire one (based in Malahide area and around)?
Also, any tips on varnishing the boards once sanded? We do not have children, so barring the occasional spill would expect to be "light" abusers of the floors...
Any help would be great....i'm sure this will be the first of many posts seeking your advice!

Thx
Mike.

Hi mike

I undertook this job weekend before last. Managed to get around 500 sq ft sone i nwa weekend, mind you that was starting Fri night and working flat out Sat & Sunday. A few tips that worked for me:

Hire abelt sander. This is a rotationg drum, it works a bit like a lawnmower - you walk it along the length of the boards. Start off with a heavy / mesium grade sand paper (these will be supplier by the hire company) and finish with a fine sand paper. rented

See http://www.kevinboone.com/sanding.html for great tips on this job

And before you do hire the sander - Make sure you get a hammer and punch out - and knock the head of the nails below the surface of the wood - Otherwise you will constantly be ripping and replacing the sanding belts

Hi MGL,

Welcome to AAM.

This post on sanding from AAMs key post on Wooden Floors might be useful.

Best of luck with the work.