Madhur Jaffrey has written a few Indian cookbooks, and I seem to recall they are easy to follow and don't assume you know the techniques. I've also had Cooking Like Mummyji recommended to me - but haven't ever looked at it so can't comment!
It is good fun making your own spice mixes. (The base mix I tend to use is from a Delia Smith recipe, so is almost certainly utterly inauthentic, but it tastes like curry
) You need the whole dried spices for things like coriander seed and cumin seed, a small frying pan you can heat without anything in it (I've got a small blini pan that I use for this), and something to grind the seeds with after - a coffee grinder or a pestle and mortar (tip for choosing a pestle and mortar - the mortar (bowl) should be solid enough not to go shooting across the work surface as you use it, the pestle should have a good weight to it).
Heat the frying pan up til it's very very hot, then put the seeds in and spread them out. WARNING: Unless you really really dislike the other people in your house
DO NOT put chilli seeds into the hot pan - the fumes will drive you all out!! Watch the seeds in the pan - after a minute or so they should start to jump. Turn the heat off and tip them into the mortar or grinder, and grind. Then add powdered spices etc as required.
Which is all more than you wanted to know,probably
