Animebytes is by far the best private tracker for anime as Fractal says. Far, far better than BakaBT in so many ways.
If you want the anime first though, groups tend to release through their IRC channels first.
All you do is look up when a new release on
Baka-Updates.com: All your Anime needs check the group IRC chan, connect to it. A lot of groups release through XDCC bots.
Not all groups have IRC chans, but this is usually where people get the stuff first: from the groups themselves. Then upload them elsewhere to other places like torrent trackers.
I've noticed a trend in groups also making torrents of their own releases simultaneously now though on sites like Nyaa.eu
The same applies for manga releases too, scanlated and raw manga is usually available through IRC first (especially the weekly manga releases since there was a crackdown on raw manga not long ago). You'll find it there first than on somewhere like Share (Japanese P2P application).