Answer:
It is contingent upon what kind of Aramaic you wish to write.
Samaritan Aramaic: http://www.omniglot.com/writing/samaritan.htm
Syriac Aramaic: http://www.learnassyrian.com/aramaic/
Babylonian Aramaic: http://www.omniglot.com/writing/aramaic.htm (Bottom square script Aramaic, which is used in modern Hebrew)