To get a good idea of what you are looking for, reviews and advice from others can be a good place to start. There is an accessible holiday discussion forum on apparelyzed.com here
If you have a particular accommodation or location in mind, trip advisor can be a good place to look for reviews by others.
Some travel companies cater specifically for people with disabilities and would be happy to discuss a destination that suits your requirements. A list of travel companies and accessible accommodation providers can be found here
Other accessible travel companies which are not included in this list are:
You do not need to limit yourself to travel companies providing accessible holidays. If there is a particular holiday you would like to go on, any travel company should be happy to research whether your requirements can be met. Communication of your requirements is key.