This page is the home of Milton-L, a listserv of all-things-Milton that seems to have been around as long as the Internet. This is a site mostly geared toward academics, though you can pick up a lot of interesting tidbits about Milton's life by poking around here.
The John Milton Reading Room is like an online library dedicated to Milton's texts. This goes beyond Paradise Lost - it includes selections from his political writings, as well as his Latin poetry. You can also read modern criticism of Milton's poems.
The University of South Carolina has put together this incredible online exhibit of Milton's life and times. Using texts from the library's collections, the exhibit walks you through Milton's childhood, political involvement, poetic career, and family life.
It's hard to keep track of all of the political maneuverings that went on in the background of Milton's life, let alone his many works and marriages. This timeline created by Roy C. Flannagan at Ohio University is a helpful guide to the events of Milton's life.
Milton's entry in this online encyclopedia of medieval literature is illuminating. It has a biography as well as links to quotes, texts, critical essays, and recommended reading on Milton.
The year 2008 marked the 400th anniversary of John Milton's birth. Libraries and universities around the world celebrated the milestone with special exhibits. Milton's alma mater Cambridge University put together this website as part of its commemoration of the student the school once suspended.