I'm linking this older post b/c it has some good resources:
http://www.dcurbanmom.com/jforum/posts/list/505938.page#7725066

Remember that flower beds are going to be more work than shrubs. So start small.

This is a great resource for native plants:
https://www.nps.gov/plants/pubs/chesapeake/

There's a handy guide to plants that attract butterflies and that means flowers (as well as host plants). So as to make it easier on you, I'd start with flowering shrubs, then add add flower beds around them.

Try here, OP:
https://extension.umd.edu/hgic/earth-friendly-landscaping

Try posting on gardenweb

I think Better Homes and Gardens has this.

We bought a house a few years ago with beautiful professional landscaping.... But it doesn't look as nice anymore, lots of brown on the shrubs and just generally realize it isn't out style. I want more flowers and not so many shrubs. I am not interested in hiring a landscaper and would like to figure out a design myself but not sure where to start. Are there any websites people can recommend which can help me visualize the layout and suggest plants that would work well?