If you use Chrome, you can download the DyslexicReader Extension. You can also download Open Dyslexic Font. This font is supposed to "add weight" to the letters to keep them from turning around or upside down.
You can adjust the size of images and text on your screen. In most browsers, you can hold down the CTRL button and press + or - to adjust the size bigger or smaller. Alternatively, you can hold the CTRL button and use the scroll wheel on your mouse.
Convert Text to Speech. There are many different options out there for converting text to speech. This site lists options depending on what browser you use.
Use Readability. This extension will pull out the main content and hide the 'clutter' of ads and other content.