For a nice list of recommended materials for “art journaling, doodling and beyond,” check out this post at the blog Daisy Yellow. Among lots of other fun supplies, these notebooks are mentioned:

Moleskine Notebooks ~ I use the sketch lined or unlined Moleskine for doodling, making lists, planning trips, drawing mandalas.

Moleskine Watercolor Notebook ~ I use these for neocolor II crayons (wet/dry), doodling, watercoloring, drawing mandalas, acrylic paint, anything. The watercolor paper is beyond fabulous. I’ve painted on the back/front of the same page without a problem! No bleed-through. Expensive but a worthwhile luxury.

Hand Book Artist Journals ~ Great for sketching, doodling, writing & journaling. The paper is so enjoyable to use, and they come in a lot of fun shapes and sizes. Love the square notebooks. We use Hand books as travel journals.