For planning your spring viewing, here's a calendar showing the weekly anime broadcast schedule for April-June 2009. It includes new shows and continuing shows, and gives highlights of staff and cast, as well as links to sites that give more info. Click the image to go to the full calendar.
The big days this season are Thursday and Sunday. The season gets going in earnest next Thursday, 2 April, with six new shows: Queen's Blade, Asura Cryin', Pandora Hearts, Basquatch, K-On, and Requiem for the Phantom. Higashi no Eden will join them the following Thursday, 9 April.
On Sunday 5 April will come a full 13 new shows: Beyblade, Dragon Ball Kai, Jewelpet, Cross Game, Fullmetal Alchemist 2, Before Green Gables (Konnichiwa Anne), Hanasakeru Seishounen, Guin Saga, Shangri-La, Tayutama: Kiss on my Deity, Natsu no Arashi!, Tears to Tiara, and Saki. Good luck keeping up with that lot, lol.
Here are my detailed previews of all the new shows. You can find other previews via Anime Nano. And there is another anime schedule here (Mahou Showtime).
You may notice some minor changes from the dates/times given in my previews. There is always a little shuffling just before the season starts. I'll keep correcting the calendar as I get new info.