There's a hole in the bucket...

[Straelbora]

I do some woodworking myself and have sold several food safe items, mainly goblets. I use and would recommend Salad Bowl Finish. If you have a wood workers supply near you then you should be able to find it but Lowes and Home Depot do not carry it. I would also suggest Rockler, they're a good company and here is the link.
http://www.rockler.com/salad-bowl-finish
I hope that helps.

Thanks.

[turnip]

Thank you everyone for all the into! Turnip is really into carving (as well as almost any other kind of art!), so we'll get some good wood, and maybe she can help get me started also! Sindara

[Straelbora]

the way they used to do it, was keep water in them. this would cause it to swell up and form a water tight seal! just submerge it and soak it in water for a day! great find! i love those buckets

I found another small wooden bucket at the Salvation Army store and tried your advice- when I first put water in it, it leaked from all over. I soaked it for several hours and there was only a slight drip. Thanks!

[Kortoso]

Beeswax should do in a pinch.

Jas Townsend sells brewers pitch.