I first learnt HTML using what has now become pagetutor.com . It has a comprehensive tutorial which you can download onto your own filespace. It's easy, it's quick, it's free, and it's fun! Viewing hightly recommended...
A really useful book on all things website-related is Web Design in a Nutshell by Jennifer Niedhurst. It gives a very comprehensive overview of the wide range of issues to consider in web design, including the relation between HTML and Unix, a concise outline of the role of the server, and loads of great tips on how to make your website as accessible and attractive to as many people as possible. It's also got an excellent chapter on CSS which is easy to learn from. Go to the fantastic bookbrain.co.uk to find out which online bookseller is offering the best price.