Had a great book for Christmas, 'The Ultimate Bird Feeder Handbook' by John A Burton, published by New Holland. Describes all aspects of feeding birds.
As for the best feeders, look at the sites selling them as well as local retailers. Birds seem more interested in the contents, start off with the cheapset and if needed up grade to the more expensive. I have had a 6 port plastic feeded for years, just brought another for £2.99 (have added a seed tray (dearer than the feeded) underneath which stops seed falling onto the ground).
Have invested in a pole system which has 5 hooks and a tray hanging from it, much better than the traditional bird table.