first time planting potatoes...don't know what to look for and when

This is my first year planting potatoes. I planted an organic blue variety from Maine.

I planted them on 4/21/14.

Looking for two pieces of information:

1. When can I expect them the sprouts to pop up out of the ground?
2. What will the sprouts look like?

thanks!

Vadim, on this page are a few pictures of the potato sprouts.

http://www.bing.com/images/search?q=maine+blue+potato&qpvt=maine+blue+potato&FORM=IGRE

When they come up will depend on the weather, I think.

1. Depends on how deep they are planted and how warm and moist your soil is et cetera. 3 weeks should see them popping up though I would expect

2 you can google potatoes growing here are a few pics.

http://www.harvesttotable.com/wp-content/uploads/2012/04/Potatoes-growing-in-straw-mulch3.jpg


http://www.amillionlives.net/wp-content/uploads/2010/11/Growing-Potatoes-in-Containers.jpg

Big almost oval leaves. bright green. They don't look like any weed I know of. If you planted them in a line and at even intervals it should be obvious

Thanks for the help! Literally the day I got all these responses, lo and behold I walk outside and...of course there were beautiful potato sprouts!

They are now about 4 to 6 inches tall.

So, I am assuming it's time to start the "hilling" process?

What would you recommend? I know it can be done with either dirt or straw... My compost pile is mainly hay that I use for my chickens' bedding. I was thinking about using that.