Energizer have some good applications manuals for their old Ni-Cad batteries (they don't make them anymore) and for their new Ni-mH cells.
They say that the Fast Charge Cell series can withstand a 1 hour fast charge but their ordinary Ni-Cad cells will be overheated. I have had many ordinary cells but I have never seen their Fast Charge cells.
Their Ni-MH cells are described very well. They recommend a 3-stage method to fast charge them safely.
Their Technical Info section of their website doesn't work today.
Maxim-IC have some battery charger ICs.