RE: "I think first and foremost I need to start amending this terrible clay soil I have."
No, really first and foremost you need to plan out what you want to do and what you want where.
If you are just going to have lawn, no point in working on amending the soil. Tall fescue, bermuda grass, and buffalo grass do well in clay soil. If you are going to put down paths, dig a pond, build a shed, etc, etc., no point in amending soil where they will be. Personally the only soil I would worry about is where you will have flower gardens or vegetable beds. So first you have to know where that is.
If you show us some pictures of your yard, with some indication of compass points, shade/sun, scale we would be glad to throw ideas out!
A few landscape design principles to start with:
Choose a style: formal, informal/cottage, oriental/Zen, desert/xeriscaping, tropical, etc
Choose a color palette: (something that goes with your house) cool colors, warm colors, high contrast (high energy), low contrast (serene)
Scale: make your plantings in scale with the house. Especially foundation plantings, people usually make way too small.
Design in curves: nature doesn't make straight lines. Houses are usually boxes and really benefit from having curved lines of gardens around them. Unless you are doing a very formal garden, make all your garden boundaries curved.
Plant from high to low. Along a fence line, tallest things at the back, sloping down to smallest in front. For an island bed, tallest things in the middle.
Here's a sample of some of that:
Notice the shady retreat in the back, curved lines, high to low planting....