Depends how deep you want to get into it...
Megs stage 1 and 2, or mentioned above, then say Victoria concours - £30 for a decent enough sized tub.
This lasts a long time and gives awesome results.
Is more cost effective than cheap waxes.
To help the polishing and application of wax, use a german pad.
Can find it all on cleanyourcar.co.uk and a few others.

Edit/ Before all that you want to use a clay bar on it, something like sonus green.