Product Price List and Invoice

Hi all, I have been using excel 2003 to create basic spreadsheets and invoice/receipts templates which are totally manual apart for basic calculation e.g. addition percentages.

I am a self employed electrician.

I would like to create a spreadsheet (from now on i may have the wrong descriptive terminology) so i can produce a parts used which encompass costing as well. From this i can use it to produce quotations and invoices.

I use no more than say a selection of say no more than 500 differing product types with there up to date costings. I've been looking on the web and have come across, databases drop down list & Vlookup. But I'm really confused.

Any help steering me in the right direction would be appreciated.