I entirely agree, Tess! It drives me nuts to see websites offering editing, writing or proofreading services and their sites are full of typos. A recent example from another forum, a VA inquired where she could get 'article templates' and wrote "I have too articles that I need to write with photos for wood working publications"... I am sorry, but if you can't differentiate between 'too' and 'two' then you shouldn't be writing articles for anybody, not to mention but 'wood working' is spelled as one word,

! I also agree that the best way to improve your skills in this area is to read, read and read some more.
Joyce, I don't offer website proofreading as a service, but have done it for a few clients. For clients that don't have Word, I would still use Word to edit the document, but you could always return the edited copy back in the body of an email showing the changes. Interesting question, perhaps someone else has a better suggestion. Good luck!