I agree with Bob, when starting out in the game the clubs should help not hinder your progress while you concentrate on the important stuff (get the grip, stance & swing right).
So, definitely game improvement clubs ('oversized', cavity backed etc - but then almost every club made in the last 5 years is this) and unless you are very tall/very short just the normal 'standard length', 'standard lie' clubs, then unless you are a natural athelete/golfers go for standard shaft (ie not stiff shaft).
So there you have it, standard everything on a set of clubs made within the last 5 years should do it ! (and ebay has lots for sale at the much less than your mum is prepared to pay - make sure you get a set which includes the bag).
Still confused? Go down to your local driving range or golf shop tell them you're just getting into the game and ask for some advice (tell them your mum is going to buy you a set for Christmas) they'll let you swing a few clubs and tell you the pros & cons of each then just tell them you'll think about it and walk out (no different to any other shopping!)
and/or ask more questions here...