This site has a really helpful feature, it measures loadtimes for your site. Once your site is up and running, you simply go to the link below, type in the URL and it measures the loadtime of everything involved, pages as well as photos.
CSS3 PLEASE! (http://css3please.com/)
This one is useful for those of you interested in CSS3 and what it can do. It offers a small window in the upper right corner of a stylesheet which displays all the changes you make to the stylesheet in realtime. What use is this? Well with the introduction of HTML5 and CSS3, there are many time and resource-consuming activities that can be eliminated from website creation. Definitely a plus when you are in a crunch. (Warning, not all browsers are CSS3 compliant yet so some of the older versions of IE as well as a few others won’t be able to use the extra code.)
W3 SCHOOLS (http://w3schools.com/)
Ok, this one is a requirement for anyone serious about keeping up with web design. W3 schools features simple, free tutorials and walkthroughs of just about anything having to do with the technical side of web development. Is this important for me as a web designer? Of course it is! Your coding skills will have to be exercised if you want to have much to do with the web.
These three will give you a few more tools to add to your web design toolbox. Take advantage of them!