Make an invoice tracking spreadsheet more dynamic (VBA if needed)

I have a spreadsheet that I want to make more dynamic. When I select a specific month (e.g. January), I do not want select each and every cell to enter the information. I want to lock all the cells because there are a lot of users who use this spreadsheet, therefore I want to eliminate any errors or erased data. This is a simple task that I can do. However, I want to have a form that pops up and asks for the information that the user should enter rather than entering it in each cell (Date initiated, part number, quantity inspected, % Defective, Invoice, projected, etc). In the month's tab where it says "Sorting Company", I want to have that also in the form that pops up, and if I want to add a new sorting company, I want to be able to do it easily using the form too (maybe a drop down list that contains the names of the sorting companies and a blank item for new companies) inside the form. I want the form to be in the month's tab where I can click to enter data. This will apply to every tab (every month). If you have any other ideas, please let me know. Please let me know how much this costs. It shouldn't be that bad.