Despite its somewhat recoil-inducing name, Mother Earth News seems to have some consistently useful and practical information. I recently, and somewhat dubiously, signed up for their food and gardening newsletter (inspired by a friend's positive experience making bread under the instruction of one of their articles).
Turns out, instead of living up to my pre-judgment and unsubstantiated assurance that their information would be full of proselytizing have-solar-power-and-free-range-chickens-or-die fervor, they've got some sensible, affordable, no-nonsense advice.
The latest cool thing I've seen (and I don't even have a garden) is their "What to Plant Now" guide, which allows you to see detailed, month-by-month information on what to plant in your garden, and when, based on where you live. It includes graphs and links to other resources as well.
According to their map, we're kind of at a climatological crosshairs between the Central/Midwest and the North Central/Rockies region but at this point in the year there's quite a bit of overlap there.
Beets, carrots, lettuce, peas and radishes are among the go's for April no matter which region you prefer to align with. The graphs also tell you which crops are more suitable for indoor planting (apartment dwellers, take note) as well as when to transplant.
There may yet be hope for me.