Background City is a useful website full of background images for web pages. The sheer amount and diversity of images means there's something for everyone and anyone looking for a background besides a solid color will be able to find one they like there.
Color Scheme Designer is a website that allows you to find any color you want on a color wheel and provides you with the hexcode for any color you find. It also has options that help you come up with color schemes, by optionally highlighting complimentary colors and so on. It is very useful when picking out colors for your design project.
This site is a website designed to help aspiring web designers by providing tips and tricks for constructing aesthetically pleasing designs, as well as making web pages practical and user-friendly.
W3schools.com is an incredibly helpful site when it comes to learning how to code with html and css. It provides a list of html tags and provides examples as to how they are used.
Notepad ++, while not a resource in and of itself, is an inredibly useful tool for webdesign from the perspective of coding html. It highlights tags, has color coding for styles and comments, and can keep multiple tabs for separate pages in one window. It is heads and shoulders over regular notepad and I highly recommend it.