Planting in Barrels

Planting in Barrels

After admiring them for years, this is my very first barrel planting. It's a whiskey barrel cut in half of course, but it has no drain hole in the bottom. I plan on growing my heirloom tomatoes in it, and was wondering about how I should prepare the bottom for proper drainage. Should I drill holes? how big? what about layering the bottom with rocks or something? Thanks!! 8)
Aliens!

Aliens!

Pretty Tulips

Pretty Tulips

And another one…

And another one…

Garden update…

Garden update…

My small room ~ tour ~ (img heavy)

My small room ~ tour ~ (img heavy)

Ahhh!  Help!!!

Ahhh! Help!!!