Aside from the obvious.....the gallery.....I love to browse through pinterest and get inspiration not only from the layouts but also look at sketches, painting, collages, art journaling and quotes.
I love combining paint/brushwork/overlays etc with clustering and can spend hours scrolling thru pinterest for ideas. It's my happy place while I watch TV at night, as I sit in my chair with no iPad.
Instagram is another one that I browse thru every single day (multiple times).
Magazines/posters/billboards too sometimes give me inspiration whether it be color, design or text.