I'm a level 61 fire mage and im struggling to find decent gear. Is there any particular items that will really help at my stage or is there any sets that are easily obtainable.

I am not an engineer so i cant make any items so i rely totally on drops.

As a mage you can make your own gear if you have tailoring. A great (and easy) way to get gear for 60-70 and then 70-80 is to buy the PvP gear sets either form Stormwind or Orgrimar. They are cheap and easy to get, another great way is to just buy the gear form other players or use the auction house.