Firstly, welcome to the forum I've been riding on and off for a year or two and i absolutely love the sport! As for your bike, it's a great choice to learn on! Decent spec, good geo, can't go wrong really! I ride a street-orientated stock (26") and have my tyres at around 25psi so it'll roll nicely for spinny streety moves, yet still holds on to walls etc well. It's personal preference really. Pump it up, ride, hop around a bit and if you don't like it, let a little air out. Repeat until you find what you're comfortable with Feel free to add me on msn if you've got any questions or just want someone to talk to Matt