I like celery, but it seems to go limp very quickly when I buy it.
What's the best way to store it to keep it crisper longer?
Trim the root end, then set the stalks upright in a tall glass, add a few inches of water, then stash in the fridge.
You'll want to change out the water every couple of days, or can get strange on you.
You can also cut it into shorter lengths, and store it completely submerged in water; this may be necessary to do with part of the stalks anyway, as most people don't have their fridge shelving adjusted to handle the full height of a bunch of celery.
If you have time, you can do some mason jars with celery. You can act like it is shown in that tutorial: http://www.salad-in-a-jar.com/skinny-secrets/salad-in-a-jar - I know it's about lettuce, but I did analogous thing with celery and it was good. And if you want quick hack, just wrap your celery in aluminium foil: http://www.listonic.com/protips/get/mshkilezox .
Store in an mostly airtight container, even a basic plastic bag with the opening folded over will do
Feel free to chop a long celery bunch in half. The cut ends do deteriorate a little over time, but not that fast, and it's better than bending or squishing them into the fridge
Just don't let it sit in moving air as exists it most fridges