Here’s a list of useful resources that would help with building, managing, debugging and optimizing a site:
- www.w3schools.com – Good reference of syntax for html as well as basic notions of php, asp, etc.
- php.net – The definitive php Bible.
- tizag.com – Tutorials with examples on various aspects of html, css, php, mysql.
- validator.w3.org – check a web page for valid html code. Some issues with HTML5 still.
- jigsaw.w3.org/css-validator/ – check a page for valid css.
- htmlhelp.com/tools/validator/ – check a page or a whole website for valid html and css.
- intodns.com – see the dns zone of a domain.
- whois.domaintools.com – registration and hosting informaiton of a domain.
- widget.webado.com/whois/ – simple whois lookup, with some dns information.
- web-sniffer.net – get http headers for any url to se server response codes. It refuses to respond to any url that has the word “video” in it.
- www.rexswain.com/httpview.html – get http headers and content for a url.
- aw-snap.info/file-viewer/ – get http headers and simulate Googlebot to help with hacked websites.
- www.rexswain.com/httpview.html – get http headers and content for a url.
- tool.motoricerca.info/spam-detector – basic spam detector for a web page.
- gsitecrawler.com – provides a program (for Windows) that crawls a website the same way a search engine robot would and creates an xml sitemap that can be submitted to Google Webmaster Tools.
- home.snafu.de/tilman/xenulink.html – Provides Xenu, a program (for Windows) that crawls a website (without respecting robots.txt) and finds internal and external broken and/or redirected links.
- canig.com – tutorials to help explain how to remove pages from Google’s index (if at all possible).
- copyscape.com – find other instances of content from one site on other sites.
- www.websiteoptimization.com/services/analyze/ – web page size, weight analysis.
- Great video by Google’s own Maile Ohye on how to hire an SEO.
- etc