Freelance work, how much to charge?


I have not done freelance work, but I had been asked to design a calendar, 12 pages (one for each month), images to be used provided by them.

I want to have a flat rate, but would like to know how I’d go about determining that.

I will also be the one printing and putting it together, so how do i determine how much to charge per calendar.

Basically the calendar is to be printed on a 4x6, full colour, glossy/matte paper, one for each month and will be placed in a stand case.

I will be needing to provide a quote for my design service and a quote per calendar.

Anyone know of a good site, that explains how to price, as well as how to create a quote?

Any guidance would be great!