a) I spent about 25-35 minutes using this website. It's not particularly large, but it is chock full of information about Thales, who is a mathmetician I'm interested in doing a report about for my own class, which is why I chose those link to look at. I mainly just read through all the different information, and I bookmarked to it so I could keep track of her sources and use the other links on the page.
b) Certainly it does present the information well. One can read her paper, see the links to other sites and basically learn all there is to know about Thales, who is educationally significant himself both mathematically and historically.
c) I don't think that this website is particularly better than any others I've seen about mathemeticians. It's good information, but for the most part, as a learning or teaching tool, is only average.
d) The material itself is easy to use, but could be better organized. Say a student just wanted some basic facts about Thales - this site would be a poor place to look for them because you have to sift through long pieces of text to get to them. However, it's still a good site, just a bit unorganized.