Hi Katherine,
Just submitting your home page to Bing is not going to do much for SEO.
You really need to submit your site maps to both google and Bing as described here:
http://www.mojoportal.com/submitting-your-site-maps-to-google-and-bing.aspx
Note that there are multiple site maps to submit, one for cms pages and one for blogs.
You should also make sure you use meta descriptions on your pages and blog posts.
Your titles, meta descriptions and actual content should also have the words you are expecting to get search results from.
Accessibility is a pretty generic term and probably a highly competitive one, it may take a while to get any search index placement on a term that generic. It is good to use more specific terms and make sure your titles, meta and article content contains it. For example you have an article about an accessible ftp server but that is neither the page title nor the article title nor is it reflected well in the url since that is based on the title.
http://www.raeder24.org/recommended-ftp-server-at-both-an-affordable-price-and-which-has-a-completely-accessible-interface.aspx
that is a very long url and page name. If the page name and heading was simply "An Accessible FTP Server" and the url was also like that with
http://www.raeder24.org/an-accessible-ftp-server.aspx
and your meta description also had something like "Our review of an accessible ftp server"
and your article also used those terms a few times in the context of the article. you can mention in the article that it is affordable and any other thing you want to say about it, but it is better to use succinct titles page names and urls that target specific phrases that you hope to get search placement on and don't include much else except in the body of the article.
Then if google and bing are indexing your site you have a ghost of a chance of coming up on a search for "accessible ftp server", but still not likely to get placement on a search for "accessibility".
I will say that I get much more traffic from google than bing though I submitted my site maps to both, and I think this is true in general that many more people use google than bing so I would focus on google first and bing second.
You home page is where you should have the most generic terms that tie together the other related but more specific terms. So if you site is primarily about accessibility you should emphasize it on your home page in headings, meta descriptsion, and article/summary text. Having "Accessiblity" in the title of your site would help as well and if you could get a domain name with the word "accessiblity or accessible" as part of the domain name it would also help. I don't know what is available but ideas like accessiblesoftwarereview.com or something of that ilk would be good, shorter is better but it may be hard to get one that you want.
Hope that helps,
Joe