You do a few basic calculations by adding everything up, footing foundation height, etc. Dong forget do deduct the height how far you want your foundation to be out of the ground to accommodate the windows you will be using.

That aside you have to know if there is a water table issue and if it that will dictate the depth of the foundation to make sure that your basement floor is at least 1' above the water table.,Further more you have to account for back-fill and final grade elevation to make sure you will have proper pitch to divert the water away.

In addition to all that you have to be more or less consistent with the adjoining properties and near by homes so the run off from your house don't flood your neighbors.

You best bet is to hire a survey company, and they will figure all that based on your house in relation to the property and make sure you will have proper storm water run-off and they will set corner foundation stakes with marked elevations for the the house and note where you need to be. From there you can make your own minor adjustments to address basement window heights, etc.

That said, it is obviously you never done that and you have no idea what to do, make sure to hire an experienced excavation company specializing in foundations because if you get someone inexperienced or an operator who don't know any better you will have one costly foundation.