how do you set up drop down menus for tabletransactions ?

[Sheryl]

I need help in setting up a tabletransaction with multiple company projects. 1) Multiple bank accounts 2) multiple paid from and to transactions, 3) multiple descriptions for transactions, 4) Intercompany loans to and from, 5)payment methods, 6) Category of multiple projects, 7) Subcategories for projects.
I have done this without a drop down menu created however, If another person does entries they are not consistant and require double/triple work to correct. Can you help me in learning how to do a drop down menu for the above described task so entries will be consist and in proper order. I know this can be done but have limited experience with Excel formating. Thanks for any assistance anyone can provide. Sheryl