You'll find that collectors prefer catalogues from their own countries:-
Britain - Stanley Gibbons
USA - Scott
Germany - Michel
France - Yvert
The main country catalogues have varying amounts of information about the stamps in their catalogues and of course the stamps are priced in a currency that is familiar to the collector.
I find that Michel catalogues have more detail about the stamps than Stanley Gibbons but then I have to try and work out the German description!
I do hope you both catch the stamp bug