[Nottingham] Making PCs from parts

[James Gibbon]

Hiya everyone,

Apologies if this is considered a bit off-topic, but I'm planning to
put together a couple of PCs from parts, as a sort of project; not 
something I've done before. Can anyone recommend a supplier of (new)
motherboards, power supplies, processors, cases and so on?

Additionally, is there a useful guide to DIY PC building on the net
anywhere, or can anyone recommend any published material on the
subject?

Many thanks
James