The following webite links are some of the best that are available as free resources for site development.  If you need scripts or design help this is where I would start.

JavaScript and DHTML
JavaScript Source
JavaScript Kit
Dynamic Drive DHTML
Java-Scripts.net
JavaScript City
April's A1 JavaScript Resources
CGI Script.net
The Free Site.com
HotScripts.com

Free Graphic Design Resources
The following list is just a sampling of what is available in free photos, clip art, wallpapers, buttons, divider lines, and banners. As a precaution, use animated graphics and high impact wallpapers sparingly, though visual, they can really detract from the professionalism of a website.

Free Graphics.com
The Free Site.com
Clip-Art.com
Microsoft Office Clip Art
The Free Graphics Store

Advanced Website Development
The following lists are some of the most commonly used free (open-source) and low cost options for advanced website functions. Most will require a server that provides php and MySql.

Blogs
b2evolution
Nucleus
pMachine Free
WordPress

Content Management
Drupal
Geeklog
Joomla
Mambo Open Source
PHP-Nuke
phpWCMS
phpWebSite
Post-Nuke
TYPO3
Xoops

Customer Relationship
Crafty Syntax Live Help
Help Center Live
osTicket
PerlDesk
PHP Support Tickets

Discussion Boards
phpBB2
SMF
YaBB Bulletin Board

E-Commerce
CubeCart
OS Commerce
Zen Cart
Agora Shopping Cart

F.A.Q.
FAQMasterFlex

Guestbook
ViPER Guestbook

Hosting Billing
AccountLab Plus
phpCOIN

Image Galleries
4images Gallery
Coppermine Photo Gallery
Gallery

Mailing List
PHPlist

Polls and Surveys
Advanced Poll
PHPSurveyor
phpESP

Project Management
dotProject
PHPProjekt

Site Builder
Soholaunch Pro Edition

Wiki
TikiWiki
PhpWiki

Other Applications 
Dew-NewPHPLinks
Moddle
Noahs Classifieds
Open-Realty
phpAdsNew
PHPauction
WebCalendar