In a recent survey done by recruitment firm, The Creative Group, they found that 68% of advertising & marketing executives think April Fools office pranks are unsuitable for the office. Some think if you work for industries such as banking, finance, or insurance you should steer clear of them however startup companies may think differently.
If you decide to pull an April Fools office prank be nice about it. Don't do anything that will put your future employment at risk or offending anyone. If you know a person well do something that you know will make them laugh. Understanding your workplace culture is important to know before pulling a prank.
Read more about USA Today survey here: http://www.usatoday.com/story/news/nation/2013/03/31/april-fools-prank-workplace/2039969/