I am going to be making some sugar cookies for a co-worker. I've never done this before and I need a stackable frosting but not so hard you break your teeth. Also, if you have advice please feel free to pass it along. Thanks. I'm not getting paid, just my pride is at stake.

The two most popular cookie icings are Toba Garrett's Glace' and the Antonia74 Royal Icing. It's a matter of preference. There are great things to say about both.

Toba's Glace'
http://forum.cakecentral.com/cake_recipe-2119-Toba-Garretts-Glace-Icing.html
Cookies decorated with this icing:
http://www.cakecentral.com/cake-decorating-photos-by-kneadacookie.html

Antonia74 RI
http://forum.cakecentral.com/cake_recipe-1983-Antonia74-Royal-Icing.html
Cookies decorated with this icing.
http://www.cakecentral.com/cake-decorating-photos-by-antonia74.html

Here is one of the best Cookie How-To's you'll ever find.
http://www.cakecentral.com/article54-How-To-Bake--Decorate-Cookies.html

HTH!

Honeydukes, THANKYOU! I really appreciate it. WOW you all have such amazing talent! Those cookies are beautiful works of art!!

I mentioned those two because they were the first examples I could think of using those icings (of course, Antonia74 after all it is her icing!). But there are so many more talented cookie people here. Here are a few more:

bakinccc
Peeverly
yankeegal
cookiemookie
MichelleM77
di55
mawagner
Fairytale
NancysFancy