Data Dictionary help

I have to use PB to put together a make believe company and must do a data dictionary along with it. Does anyone have any good links to examples of a data dictionary so I may have an idea on how to do one and what info I might need to put together. It's a small service business, that needs order entries, ledger accounts, goods and services, entities, pricelist reports, sales report, customer list, purchase order, net zero, trial balance... among other things and also a good link on how to do a UML diagram of the project. Rational Rose is a requirement but it's a new software to the labs and so don't have much experience with it. Looking for good tutorials on B-liners, and/or Rational Rose also.

Thanks for any help give, I really appreciate it.