Hi Lee.
http://atbutterflies.com/ is a useful website, from which you can download (in many sections) a digital encyclopaedia of African species (for a subscription).
There are several handy guides to common African butterflies, including the Collins handguide by Carcasson, the Field Guide to the Butterflies of Africa, by John Williams (both those books are now very out of date), and the Pocket Guide to Butterflies of East Africia, by Dino Martins. None of these is comprehensive, but they give pointers at least and cover much of what you will see. More complete is Kielland's Butterflies of Tanzania, which will have a good selection of the Ugandan species and is currently on offer at Pemberley Books for £25. The old single-volume d'Abrera Butterflies of the Afrotropical region can be picked up for under £150 but this is also now very out of date and has numerous errors. The colour printing leaves much to be desired too. The new, three-volume edition is much better (it's gorgeous) but will put you back several hundred pounds.
Guy
