First, Please excuse my ignorance. I am buying my first house and I know nothing about landscaping but I can't wait to get started. What is the best way to start a new lawn over and old lawn that is ugly and has lots of weeds. It looks like there is a couple of different types of grass mixed in. I know the best way is probably to buy new sod but I just cannot afford that. Can I put down seeds over the old grass and expect it to take over?