Decks, Patios, Porches and Docks - Joist sizing

I am designing a mezzanine for the space above my workshop in the garage. I plan on using this space for wood/lumber storage and other miscelaneous stuff.

Two questions:

1. What would be a typical loading that I should use for the design?

2. Once I know the loading, how do I go about sizing the joists?

The mezz will be 14' long X 10' wide. The joists will run in the 14' direction with no support column. What size joists are required for a 14' span? Is there a website with an online calculator or chart that I could use?

Thank you.

Tom:

This site should give you most, if not all, the information you need...

http://www.umass.edu/bmatwt/span_tables.html

My guess is that a #2 2x10 is going to be what you will use. Because of the additional load you might want to use 11 7/8" I-joist on 16" centers and call it good.