Your local garden center should have them planted and ready to bloom right now. In my area, they are most commonly available as planted starts in mid to late summer but you can find them in most complete bulb catalogs as well (like Brent and Becky's) in spring with the other summer bulb offerings. They are also available mail order from places like Heronswood/Burpees and other mail order nurseries.

Here is a link that might be useful: Big Dipper Farms - crocosmia