Okay, my friend and I are going into business for ourselves. We have a fairly solid plan of what we wish to achieve with our business currently, but we decided that we should make it a little more professional... Which is where the database comes in.

I began a simple one in Microsoft access, but realised how much I've left out. So, now I'm looking for help designing it. I'll post what I've got for ideas currently, and ANY help would be greatly appreciated.

Well, currently what we're looking to use it for is fairly simple. We're mostly orientated around phone repair, such as iPhones and such, so that's what the database is mostly going to be geared towards.

What we need is something to hold customer details, repair details, stock we currently hold for repairs.

The idea
Software: Microsoft access.

Customer table:
Name of the customer,
A customer ID,
A contact number.

Stock table:
Type of stock (ex: screen, battery, port),
The name of the piece of stock (ex: iphone 4s screen, ipod battery),
The cost of the item (ex: 10 from supplier),
The amount we have in stock,
The supplier,
The charge we'll add to the order because of the piece (ex: 15 towards order total).

Product table:
The type of product,
the name of the product,
the manufacturer of the product.

Cost table: (A separate table for costs in order to make the order easier.)
Service name,

Order table:
Who the order is for (link to customer.),
The date of the order, the product being repaired (link to product.),
Serial number of the product,
The items used in the repair (link to the stock table),
Completion/deadline date for the order,
The cost of the order (Add together all of the pieces from the stock table used in the repair + a charge from the cost table. << This is the part I'm most stumped at how I'll implement.)

Probably gonna need to add some forms for ease of use too, but obviously I'll need to get down the tables to a point first.

Now, I'm aware most of this is straightforward, but I'm stumped at how I'm going to create the cost of the order, considering it'll need a way for me to specify which pieces were used in the repair (I have NO idea how I'll do this, literally none.)

I'd love for some input, ways to improve, etc.