Hey, i'm very into this and read some cards myself, still got a lot to learn though :)
There are some very good books out there. As regards cards the best ones to get are the ones which feel right for you. Some suggest buying a special pouch, they do some lovely ones in silk and velvet and such and sleeping with them under your pillow to connect with them and you can meditate over them too. Just go with it and see what comes to you, don't force it or try too hard.
Don't rush it or try to run before you can walk, take the time to read, develop a connection with your cards and encourage your intuition, it's not really a textbook subject, you will develop with time and practice. See if there are any local groups or classes or more experienced readers who can help and support you, everyone has their own way though and you need to find that rather than try to mimic someone else's way. Or see if your sister will help you.
They do sell them in some shops such as WHSmith and Waterstones but try a local specialist shop or go to a fair type event to get some advice and have a far wider range to choose from.
I have some proper tarot cards but some other similar fortune cards I have seem to work far better for me and the results can be quite amazing :) They also tend to be simpler and easier to get to grips with as tarot can be very daunting for a beginner.
I always tell those I read for that it's guide and not a self-fulfilling prophecy.
Good luck and enjoy x