Yikes I hope this is in the right place! I have a question for a cake I am making for my daughter this weekend.
I am making a two tier cake-Do I need to put cardboard under the top layer?
Yes and some supports, for small 2 tiers I use straws. I use the large bubba straws.
Hi and Welcome to CC, madhousewife. 
Decoding CC acronyms:
http://www.cakecentral.com/cake-decorating-ftopict-2926-.html
Everything you need to know to bake, assemble and decorate tiered/stacked/layer cakes:
http://www.cakecentral.com/cake-decorating-ftopict-605188-.html
Above thread has popular CC recipes for: American b/c using either Crisco or hi-ratio shortening, doctored cake mixes, and fondant.
Also has links to baking and decorating help. In addition to links which illustrate all the common cake supports systems, with photos and complete directions.
HTH
Thank you all very much! I will make sure to pick some of that up tonight! I am hoping I can make a nice cake, this will be my first tiered one.
Since I am pretty new to it to, I will give you what I have learned. Make and ice both cakes before placing them on (ice the top one on the cardboard, so you can lift and place it on using the cardboard. I usually take another cardboard piece (that is the same size, you can buy these at Michael's or Joann's) and center it on the cake (P.S. I have made too many that are off centered, so I learned this the hard way) mark with a knife exactly where you need to set it and then I stick some thick hard straws in and cut them even with the cake and then set your top layer on. It works great! GOod luck and enjoy!
Quote by @%username% on %date%
%body%