You cannot absolutely protect yourself from liability by disclaimers or waivers, though they do help--they can provide protection from damages arising *other than* from your gross negligence (more than ordiniary negligence) or intentional wrongful acts, but will not protect you from gross negligence or intentional acts. You should have both: have disclaimers, etc. on your website, and have people agree to a waiver in signing up for your services. To provide additional protection, make sure you have adequate liability insurance and consider setting up an LLC and carrying on your business under its umbrella (which will help protect personal assets from business debts or judgmentments).