The LSE Politics Blog seems to know that you are all about to start revising electoral systems as it has a brilliant post this week outlining the workings of each of the electoral systems.
If you are ensure of the mechanics of the five systems used in the UK this is an excellent place to start:
Equally if you want to look at the impact of the systems in more detail the LSE blog points you in the direction of the following sites:
The first is drawn from the early years of the Blair government and responds to the Roy Jenkin’s proposal of AV+, although AV+ appears to have been kicked into the long grass the commentary on FPTP still makes interesting reading.
The LSE blog also points you towards the Democratic Audit website- I have included links to the best articles on the topic of electoral reform below: