Congratulations on your new house. Here's a website that i've used
http://www.bhg.com/bhg/gardening/
There's alot of good information there. Look over the yard and try and see how much shade and how much full sun you'll have in the summer. If you have a local garden center go in a couple of times and look at what they have. Usually, other than a few tropical plants for summer, they'll carry what is acceptable for your plant hardiness zone. Most of PA is the same as Michigan. Look for colors and shapes that are attractive to you. Check out the labels to see what the size when fully grown will be. The soil needs to be healthy to grow healthy plants so you'll want to figure out what soil type you have. Sand, sandy loam, clay... that will also help on what types of plants will grow in your yard. Ask your new neighbors, check out what they're growing. Usually people are willing to share when they have to thin out plants. It;s fun and relaxing. I love to dig and plant and move plants around.
OH, it's my 500 post...