3 simple things you can do now that will help make your site much more accessible right now.
Use alt tags for all graphics and graphical elements
Make your hyperlinks meaningful and not just "click here" and
Use tables without nesting them and with a brief, one-line description such as "A 3 by 6 table demonstrating the growth in taxes over 3 years, 1997-1999."
Some General Hints about Universal Design to Keep in Mind:
Simplify: this needs just a little clarification. Making a web design that is simple is not the same as making a design that is boring. Text data that says nothing or says it badly is boring. Adding a lot of pictures to bad text does not make a good web site. Novice web designers love to experiment with color and pictures and animation and blinking. Novice web designers are as easy to spot as a child's crayon drawing is in an art gallery (Modern Art Galleries may not be included). Focus on a simple presentation of rich material.
Data over Cosmetics: If your site does not give your audience any meaningful information, then why do you have a web site? If you web site is to convey meaningful information then why hide it behind cosmetics? If a graphic is not necessary, then apply rule 1 above; if a graphic is necessary then make sure that everyone is getting the data.
Speed: If a site takes too long to download, then it will see reduced traffic. If the site means to exclude a significant part of its audience then a very slow download is perfect, otherwise, see Rule 1 above. If your web site is confusing to get around and you always feel lost or it takes minutes to find something important, then it wasn't that important or else you missed Rules 1 and 2 above. If your audience has to hunt for what's valuable on your site, then expect to keep your light under a bushel or your treasure buried.
Audience: It's not called the World Wide Web for nothing. Why not reach the widest possible audience with your message, your sales pitch, your teaching? Why increase the gap between those who get it and those who don't? My audience is specialized, you might say. Does that mean your design has to limit your audience as well, shouldn't the data in your site determine your audience and not its accessibility? The idea behind the Internet was not to limit your communication but to expand it.
Roadblocks to Accessibility and Universal Design:
Too many sites with too much vague and contradictory information to sort through
No clear cut, simple steps to designing or bringing a site into compliance without a lot of hunting
Retraining designers to re-think their design strategies is necessary
Burdening faculty with more information and barriers to their teaching is a bad idea
No easy way to test sites that is reliable and accurate (easy is the optimal word)
Having to decide how much responsibility belongs to the designers and how much to the various software and hardware manufacturers
Invisibility of the need coupled with no administrative decree or support from many academic institutions
Money, time and expertise
Brief Descriptions of Why Some Web Design Elements are Inaccessible and How to Avoid them without Taxing your Resources:
Add alt tags to all images, pictures, graphics. Do not put in any graphics that do not have an alt tag. Make the alt tag more important. Make the alt tag meaningful.
Frames. When in doubt about using frames and how they fit in with accessibility, do not use frames. Frames may be used, but even when frames are properly titled and not nested; frames are still less accessible.
Tables. See Frames. Tables are always less accessible. On the Internet and in html code there is no adequate way to align text and/or objects that does not include the use of tables. This is something that should be addressed at the html code level for the future. In the mean time there are hints about tables. 1. If you must use tables for alignment, do not use nested tables (tables within tables). 2. If a table is used to present data that would normally be in a table, make sure that the columns are labeled, that the table reads left to right, column to column, and always give a caption with the table, and usually a text interpretation of the table.
Style sheets. Use them. If you don't understand them, then you should learn. Style sheets are huge time savers and they also make your site much more accessible. Style sheets are basically a small document that lists all the style elements for your page or site including font, heading sizes, colors, etc.
FONT, BOLD, ITALIC, B, I html tags. See style sheets. This html tags do nothing for screen reading software except have them read out loud, "Less than, Font equals Arial, size equals 3, color equals FFFFFF greater than, A man went to LondonÉ.." If this information was in the style sheet, then the reader could read the actual data and not the html code. "A man went to LondonÉ.."
Emphasis and strong tags. In html, italics and bold can also be shown with the <EM> and <STRONG> tags. The advantage to using these tags is that the screen reading software will actually change its voice inflection to reflect the emphasis of the author/designer. Note: only use for real emphasis and not for cosmetics.
Scalable Fonts. Do not fix the size of your fonts as absolutes or use text that is actually a graphic. Why? People with vision limitations of various kinds (I forgot my glasses) can enlarge the fonts to compensate for the situation at the moment. Also, reading on the Internet is straining in general, so even people who may not need to increase the font size will do so for ease of reading.
MOUSE nono's. Do not use the mouse to navigate on your web site. Try getting around your site with only the tab key, enter key, and just the keyboard period. Many, many people do not or cannot use a mouse with the Internet and if they cannot get around easily on your site with key strokes, then you are putting up roadblocks to your communication.
COLOR. Do not use color on the web to convey information. Why? Some people are color blind, it can be distracting, it can be misunderstood, it can make your site harder for people to navigate.