Hi,
I must confess early on, whilst used to Excel, I only use it for basic sums and sorting etc, so not in any depth.

I recently became self employed, and after using a few different software packages, decided for now to use Excel itself.
This obviously lends itself well, but at the same time I need to customise a spreadsheet for my accounts, and another for Invoicing.

I am after some help with these - if possible.?

Accounts
Quite simple for now.... I have a few columns, Money In, Out, Due, etc. Now I want a column for mileage costs. Currently I work it out, and add the amount. Eg: 10 miles @ 45p a mile - so I add £4.50 to the cell.
What I would love to have, if possible, is for these cells to have the formula pre entered but hidden... and I simply put in that cell the mileage.
So whenever I add the miles for the job, it comes up with the end result of 'x' multiplied by 45p.

I would also like the columns to be coloured (which they are), and keep these colours.
Currently if I insert a row, it will copy the colours on the row above, or will go to default black.

Invoicing
This is a little more involved. I have used a spreadsheet from the web to start it off.
The one I am using has a page with customer info (address, phone etc) and when I input their name on the invoice, the address pops up. Great.... except I would love to know how to do this, as I may take it a little further.
I could perhaps use another page for products etc.

What I would also love, is to know how to make it into a template, but one that remembers the previous invoice number.
I am having to check each time, and then input it manually. And if I save the current one, it saves everything as is, and not a blank template.

Not sure if these are possible, but I would appreciate any help.

Regards,
Chris