There are many sites where you can gather information and help on designing your website, here are a few to get started:

Information on designing your web site
http://www.becta.org.uk/websiteawards/effectivedesign.html

Dreamweaver Tutorials
http://www.macromedia.com/software/dreamweaver/productinfo/tutorials/

Mock school web site
http://www.sutton.lincs.sch.uk/pages/tes/site/jbhome.html

Model school web site which can be copied and edited copyright free
http://www.sutton.lincs.sch.uk/pages/tes/

Examples of some award winning sites
http://www.becta.org.uk/websiteawards/index.html

Sound advice issues of safety and web design
http://safety.ngfl.gov.uk/?s=3

Download Dreamweaver for a 30 day trail
http://www.macromedia.com/software/downloads/

Html Tutorials
http://www.demon.net/helpdesk/products/homepages/tutorials.shtml

Internet safety issues
http://top.ngfl.gov.uk/cases.php3

Sound advice from Kent teachers web development project
http://www.kented.org.uk/ngfl/webpub/index.html

Advice, tips and information from the Wokingham web design project
http://www.wokingham.gov.uk/websupport/default.htm