Ending a relationship

I am ending my relationship after being married 21 years. I have lived with lies, violence and no trust for a long time. there are many reasons i am ending it and i know deep down its for the best. i need to know about getting a divorce. i have seen the web sites on line to get a cheap divorce and want to know are these any good, genuine and if anyone as ever used them before. The solicitors costs so much and i think they have stopped legal aid now.