Here are some websites that I find very useful or inspirational:
http://flypapertextures.blogspot.com/ – you can purchase textures here or just take advantage of their tutorials and peruse the blog.
http://www.michaelortonphotography.com/ – heard of the Orton Filter or Effect – this is the creator. Check out the impressionistic work of Michael Orton.
http://www.digitalfieldguide.com/ – need some inspiration. Check out the work of Harold Davis. He does some very nice floral work.