Do you have a lawn planted now? are you trying to have more mulch beds and less grass?
What is your landscape design / philosophy? Cheryl provided an excellent site. If you are going for a Xeriscaping type landscape, design can be modified for maximum coverage.
It depends on what you like. We have all mulch and landscape in our front yard. Easy maintenance and pretty.
It depends on the look you want. The mulch should be at least 2" deep to keep out weeds.