I was amaized when I understood for the first time that what christians have believed for so long on this matter was not and is not true.
The most important thing we must grasp is "God loves a cheerful giver" Ok so do we tithe or don't we?
In an answer NO.

There will be times when you will give most certainly but to whom and why has nothing to do with the tithe of the Old Testement.

Click links to listen to a 4 part series dealing with the subject in full.
Pt 1
Pt 2
Pt 3
Pt 4