a video on graphing exponentials using tables
Source: http://www.youtube.com/watch?v=7fpazNs1ZRE
a video about using transformations
Source: http://www.youtube.com/watch?v=6Db1wG_zudc&feature=related
Source: http://www.examsolutions.net/maths-revision/core-maths/algebra-and-functions/log-exponential/exponential/graphs/tutorial-1.php