too make sothing like google docs is very very hard if you are just starting off i suggest you make your self a dynamic cms where you can update content online est
if you want to go down the word proccessing line type in google tiny mce have a look at that you can intergrate that into you php site
ask for any more help :p
I'm 16 and I just started getting into web based programming and one of my goals/projects is to start a web-based word processing company and website.
As far as I'm aware, html, css, php, mysql and jquery would be able to do this for you quite nicely, however with every letter you type getting saved to the database, say you have lots of users all entering data, you will soon find that server resources will be come an issue.
it is totally possable but making something like google doc will take years for one person to do no matter what exsperiance you have!
have a look at tiny mce editor and fckedior i think it is what you want.
plus it is very easy to use.
server resource may be a issue but you are not going to get that many users any time soon lol