Here are some site which should help to develop web/html skills - or remind you if your knowledge is rusty.
The OU WEB GUIDE is a very basic guide on using the internet you might pick up a few tips and can skim over the parts that you don't need. Most people find out how to use the internet just by diving in and using it, but that can mean that you have missed out on tricks if you don't use it that often.
SAFARI - is an OU online course on finding resources online and evaluating and organising them
If you want to start coding up your own HTML, crop images etc. you may find all you need at the University of Leicester site but there are also lots of sites which offer more in-depth approaches geared to particular skills or applications, e.g. How to resize and crop and alter images in MS Picture Manager (which you will have if you are using MS Office).
Webmonkey is an established site for the more challenging stuff. Its a really nice site. Not academic so less dull than the above. Check out the Tutorials list.