|I'm not sure what your "level" is, but I think I'm going to agree... this is sounding like some "advanced level" content.|
The 5sheets is cake... a template will be best rather than a macro... buttons to navigate from one sheet to the other will be macros; fairly simple if im understanding correctly... (the sheet tabs at the bottom of the workbook wont work for you for some reason??) As for the buttons to calculate a SUM, not exactly difficult, but many factors will come into play. But from what it sounds like, using a template and a combination of macros may be just want you need!
PM if you'd like. I have a CRAZY work schedule but i'll see what I can work out for you!!