Force Flowering Branches
Prune branches off flowering shrubs such as forsythia and apple, and bring them indoors to force into early bloom. Trim the branches to a reasonable size for your vase, then cut an "X" in the bottom or mash the bottom few inches of the branch to increase the surface area for water absorption. Place in a water-filled vase, and you should have flowers in a few weeks.
Wait for Soil to Dry Before Planting
Although it's tempting to get out and plant on the next 60-degree day, wait to plant until the soil has dried out and warmed up somewhat. Most seeds planted in cold, wet soil won't germinate, and many of those that do germinate will succumb to rot. Also, working in wet soil compacts it and damages soil structure. Pick up a ball of soil and poke it with a finger; if it crumbles, it's dry enough to work in the garden.
Set Up Cold Frame
Cold frames are handy for hardening off seedlings. You can make a simple cold frame by placing hay bales along the perimeter of a rectangle, and placing old windows or a glass storm door over the top. Purchased cold frames are convenient, and some even have thermostatically controlled tops that open automatically when the temperature inside hits a designated point. Since the midday sun can heat things up quickly, this feature is especially handy if you're away for long stretches during the day.
Organize seed packets by planting time. Group seeds to be started indoors, then arrange them by planting time. For example, start with seeds that should be planted indoors eight weeks before the average last frost, followed by those to be planted six weeks before, then four weeks, etc. Do the same for seeds that will be direct sown in the garden.
Begin Fertilizing Houseplants
As the days grow longer, your houseplants will be resuming vigorous growth, so begin fertilizing with a soluble fertilizer. A seaweed/fish emulsion blend is a good choice, but look for one labeled as "no odor" to avoid the usual pungent smell. You can fertilize monthly at the label's recommended dilution rate, or fertilize every time you water using a quarter-strength mix.