Hi msand,
It sounds like this will be mostly for your use, which will make your life a lot easier. The biggest pain about Access to me (or any front-end for that matter) is that you have to make it impossible for even the most computer-illterate person to foul up.
I think most importantly, before you even get into the Access end of this project, well, hold up-
Do you have to use both programs? I see this scenario frequently and many times it is possible to achieve the desired end result using Access or Excel, not both. If you think this is an option, skip the rest of my post, and repost with which you want to use..
Yeah, before you get into the Access end of this, you want the Excel end of it set up correctly. In order for Access to pull data from Excel without going to great lengths, you need to organize your data in tables, with field names starting at A1 and going across left to right, one field per column, no blanks. You also need one row per record, no blanks (you can have blank fields, but you must at least have a primary key).
If your spreadsheet has users entering data in a format other than this, which is very likely, you can create a 'data' sheet, that consists entirely of reference to the other sheets, but formats the data in this manner.
Next, go into Access, and select File|Get External Data, select to import or link to your Excel tables, and use the file browser to go find your Excel file, make sure to set the fiel type to .xls If you use linked tables, you won't have to keep reimporting the data to keep it fresh, but the data will reside only in the Excel file, if you delete it, your data is gone.
Now you're in Access with your data in nice tables, and its time for relationships, querries, reports, forms, vba, SQL and all the glory that is Access.
I'm sure you'll need more, so please post back.