Where can I find beautiful flowers for my garden?

Flower dealers, who also love them!
aha
there are many dealer..who grow just to deal in them! grr hate them. cuz then later then die faster cuz the dealers did not take care of them properly.

Do you want to buy live plants, or would you rather buy seeds and grow them from scratch? If plants, go to your local Wally World, Lowe’s, Home Depot or other garden supply center, as they will provide you with flower plants that are good for your gardening zone.
If it is seeds for which you are looking, then you can access many, many good seed catalogues online, and purchase them there, or request a catalogue.
Again, if it is seeds you want, post another question and this time input either city/state of your residence, or your gardening zone.

http://www.valueseeds.com/index.html

http://www.johnnyseeds.com/default.aspx

http://seeds.thompson-morgan.com/us/en

And a whole web page devoted to lists of seed catalogues:
http://dir.yahoo.com/Business_and_Economy/Shopping_and_Services/Home_and_Garden/Lawn_and_Garden/Seeds

Happy Gardening!

your local nursery