Cascading Style Sheet (CSS) allow to adjust the look and feel of your website with a style sheet. It controls how text looks on your entire web site. Make use of CSS to maintain your whole site.
Choose font size that is large enough so that your visitor can read the text easily. Webpage is not the place to show off your fonts collection. The most important is to let your visitor read what is written on your site.
Black-on-white always gives you the highest contrast and it can improve the readability. You can make use of colour background but do gives enough contrast with your texts. The more contrast, the better.
Break the text into different paragrpah and associated with a headlines. Headlines can gives a good highlight to visitor what the paragraph related to. visitor can scan and read your text easily with the headlines.