Ostara (Eostre, whatever you call it) was not originally celebrated by the Celts, as far as I know. I've read some books that claim it wasn't a typical Sabbat, but what I call a Quarter Day instead. That's how I view it, but people who are closer to Recon don't really, I don't think. I picked up celebrating it from when I was trying to be Wiccan, and it stuck.
As for celebrating, I have no idea. I'll probably write a poem about spring time (if I do, and it's not complete crap, I'll post it in the writing section), maybe some kind of drawing or painting too. I'm pregnant this year for the equinox, which means something special to me, so I might choose that day to start my baby book. That actually sounds like a really good idea for me, lol. Oh, and spring cleaning leading up to it (morning sickness permitting) and a house blessing. If it's a week day, I might do some kind of morning salute, since I'm up with the kidlets anyway. Haven't been getting much sleep, and with the baby, I'm not going to interrupt what I can get, I'm sure the gods understand. I'd love to cook, but the members of my family here won't eat anything I cook.
Sorry this was a bit rambly, I actually had no real plans when I found this thread.