I saw a few people point out that Tae Kim’s site was down. Checked myself and saw the same, so I found a link to a backup version of his site here. Reading his Twitter, he was hacked and is in the process of rebuilding everything. Really crappy situation, but if anyone was using his site for grammar, at least he’s got his backup running.
Tae Kim's Site Down
SleepyOne
#1
New People Questions! ~~~<3 [Lost?! Confused?! We're here to help!]
文プロ(Bunpro) : (Update: Ghost Reviews) Japanese Grammar SRS Study Site
SleepyOne
#3
Yeppers, that appears to be his work in progress as he’s rebuilding, so no real content as of yet.
rfindley
#4
In the meantime, The Internet Wayback Machine has a relatively recent archive:
https://web.archive.org/web/20170923023735/http://www.guidetojapanese.org/learn/