SLSFree.net is a website that essentially lists various available brands of toothpaste that do not contain sodium lauryl sulfate, alternatively known as sodium laureth sulfate. This website also has a list of kids' toothpastes that are free of sodium lauryl sulfate.
The list at SLSFree.net serves as a reference point for further research. Most of the featured brands maintain a website with more in-depth details about products, such as Xyliwhite Refreshmint toothpaste by NOW Foods and Tom's of Maine Clean & Gentle toothpaste. Tom's of Maine's website provides a product information page about Clean & Gentle that gives a complete rundown of ingredients, each ingredient's purpose and the source that Tom's of Maine utilizes to obtain the ingredient.
FreySmiles.com and Organics.org are other sources of information about brands of toothpaste that do not contain sodium lauryl sulfate. The former is the website of Dr. Scot Frey, an orthodontist who recommends Tom's of Maine Clean & Gentle or Sensodyne Pronamel. Although Sensodyne Pronamel specifically protects teeth from the harmful effects of acid erosion, it is also free of sodium lauryl sulfate. Organics.org focuses on organic health and beauty aids, including toothpaste brands that are free of fluoride and sodium lauryl sulfate.