Maths and Statistics Help (MASH) at the University of Sheffield has an excellent guide on deciding which statistical test to use
For online help with a wide selection of statistics topics take a look at the resources on StatsTutor
The Khan Academy offers a selection of video tutorials on probability and statistical topics.
Topics covered include:
StatsTutor has a short video tutorial demonstrating how to test the normality of data using SPSS
Testing Statistical Assumptions in Research by 
Statistics explained by If you would like to set up an account to access Integral, email: eresourceshelp@reading.ac.uk and we'll do the rest!
See our reading list for further resources related to statistics available from the Library