For the mage, any spell wtih an aiming reticle cant be macroed (i.e. blizzard)... all others should be able to.

The paladin one is easy... if you want to fine tune it youd make one macro for each ability bound to different keys... if you just want a button to spam so you can concentrate on your mage, youd do a /castrandom consecration, crusader strike etc etc and cast random will pick a spell to cast that is not on CD at the moment.

Here is a the guide for making macros,

http://www.wowwiki.com/Making_a_macro

Good luck.