Hi Allison,
Welcome to the wonderful world of gardening! It's always best to add lots of compost to sandy soils to help moisture retention and add nutrients. You can use these sites to search with your zone as you don't say what the sun conditions are. Look for those that either like it dry or need good drainage.
http://bestplants.chicago-botanic.org/query_simple.htm
At this site you can start your search by zone and then add conditions at the second page from the drop down list on the right by holding down your Control key to refine your needs.
http://www.perennials.com/
There are roses that were developed in Canada and do very well in cold climates. They are called the David Austin roses. I think you might find this site helpful. They have forums on just about anything you can think of including 'Roses', 'New to Gardening', 'New England Gardening', 'Roses' and many many more. If you decide to post the same question on more then one forum be sure to change the title of your post or their computer will think you are spamming and block you.
http://forums.gardenweb.com/forums/
Hope this helps,
Newt
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.