Get yourself a lot of spices. You'll look at the ingredients for a curry and think 'wow, thats way too much to get' but trust me, once you have stocked up on all the spices then you are set and can make pretty much any curry you want. Some spices you will need..
Cumin, turmeric, coriander seeds, ginger, chilli powder, garam masalla.
You'll need a few fresh bits when making the curry like coriander, onion, garlic, chillis.
If I'm making Indian curry then I'll make a curry gravy 1st then you can use this as your base sauce and add various other ingredients, depending on the curry. Just do a google search for Indian curry gravy.
If you are doing thai (which I love!) then I like to make the different pastes in advance and then put them in the fridge or freeze them. Favourites are thai green, thai red and massaman.
Best thing to do is a quick google search for them, pick one you fancy and go from there. Its trial and error but you'll soon be making curries exactly how you want them!
Like I said, stock up on all the spices. Took me a little while but I've now got 20 different spice containers that all come in handy for various curries etc. I love spicy food!