[AstralTraveller (David)]

Variables are something I'd also like to get into. Try visiting the AAVSO website http://www.aavso.org/ or the RASNZ variable star section http://www.rasnz.org.nz/vss/vss.htm. I believe that if you contact Pauline Loader through RASNZ she has CDs with useful resources that you can get for cost.