I wouldn't be planting anything until the danger of frost is over. I am in zone 5, Southern Ontario, and I will not plant until the very end of May or early June. I will however harden the plant off, and take them out for sunshine and a warm rain when I can.

Beckerster,
I keep a stash of old sheets and blankets to cover up the plants at night. That way I can take advantage of the warm days, without losing plants to the few really cold nights. The local weather forecast gets checked on the internet daily. My house is about two degrees colder than the weather forecast for my area. I cover the plants up if it's predicted to be lower than 35F.

Oh, I keep some garden wire fencing around to make 'hoop-houses' so the blankets don't crush the plants. Also, it helps that I don't usually have to be to work until about 8AM or later, so I can uncover them when the day has started to warm up.

Beckester, even in your area I would wait to plant the majority of plants until mid May [or until night temps remain consistently in the mid 40's or better]. Don't get suckered in to doing alll sorts of intensive planting -- especially not with annuals -- at this time. We've had an unusually warm period here this April. Doesn't mean that cold temps are done and gone any more than a 'January thaw' means winter is over. That said there are cold hardy perenials you could plant at this time such as lily bulbs.

You might check for your local area frost date. Van Atta's here by Lansing won't warrenty plants purchased before May 13th, I think is the date. That is the local area frost date, a usual time when you can still get frosted.

As others have said, you can set the plants out and cover them on cold nights. I have some stuff I potted up early, since store was selling and it was sprouting in the bags. Peonies, daylilies, regular Lilies, a tree Peony sent in the mail.

Pansies are good to set out now for color, like cold weather. I would not be planting any annuals, or big leafed perennials from a nursery. They would take the cold hard, probably die, or be poor all season. Maybe you could go out in your garden, maybe split/divide some perennials that needed it and relocate them now. Change a bed you were not happy with last season. Some things have leaves while others are still just crowns or stubs in this early season. Outside perrenials moved early don't seem to have any problems coming back well. Clean out the sneaky grass in beds. Spread compost or some granular fertilizer to give a better start to plants.
Any working in the garden should be decided by how wet the soil is. Any dirt that packs when you close your handfull, is too wet for digging or walking around on. Will really compact dirt down with digging and weight. The dirt should be crumbly, not a ball, after closing and opening your hand on a fistfull.
We had fields of frost this morning. We are expecting more of the same for the next several days of cold. I am doing some shrub trimming, cleaning off the sawdust on roses since they are sprouting. We lucked out with rain on Wed (Yayy!) so too wet to dig here.
Sorry, you can't hurry Mother Nature!

They had our forecast down to 27F last night, and we bottomed out at 33.8F without any frost. I'm so glad we dodged it big time last night!

We got to 31-but with the wet dripping snow all over everything nothing froze. I almost think the wet snow had an effect similar to what sprinkling does-plus 31 won't damage much and aside from some tiny corn sprouts (which are OK) and cherry blooms (lost a few from the wind but none froze) I don't have much out yet.