I have posted a page "Garden Planning" above, which consists of a chart with columns for each crop; the number of plants per square-foot; the date for starting seeds indoors (if necessary); the date for transplanting; the date for starting seeds outdoors; and the date of the earliest likely harvest.
Here are the steps I used in planning this chart:
1. Plan out the crops we will grow based on what we actually eat. Surpluses are good, of course: it is a blessing to be able to give food away to friends. However, there is an opportunity cost to growing a ridiculous surplus, because that garden space could have been used to grown something else you really needed. (For instance, I really wanted to grow some butternut squash because Kristie makes this incredible squash soup. But then, when polling my family, I found out that I was the only one who really liked the soup. Squash takes up so much space, so for us, that space could be better used for something else)
2. Determine the last spring frost date. Many in this area push the envolope on this one, but I am playing it conservative and using Saturday, May 5 as my last spring frost date. The timing of everything is based on this: when to start seeds indoors, when to transplant, everything. I could push that date forward a bit, but I figure with the work involved in starting seeds early, I am already getting a head-start: why risk unnecessarily risk damage from a late, unexpected chill?
3. Using chart "Outdoor Planting Schedule for Spring and Summer Crops" on page 254 of Mel Bartholomew's Square Foot Gardening, I came up with all the dates to seeds starting, transplanting, sowing outdoors, and expected harvest. Notice that all my dates are on Saturday, because that's the one day I can reliably accomplish these tasks.
This chart, then, gives me my marching order from week to week. Apart from this kind of planning, I know way too many vital tasks would be neglected.