As of June 2015, websites for This Old House, Ace Hardware and DIY Network have helpful information about sealing basement walls. This Old House lists six steps that give an overview of the process. A video with general contractor Tom Silva provides further details.
Ace Hardware begins by identifying the causes of basement leaking or seepage, such as poor workmanship, house settling and water pressure. Directions describe how to repair cracks or holes in the walls. The site then offers detailed instructions for applying a waterproof coating.
DIY Network begins by telling homeowners how to identify different causes of basement water, including condensation, runoff and groundwater swelling. The site has descriptions of two ways to fix the problem: using a concrete sealer or installing a polyethylene membrane.