Occasionally spam robots will target your site with comments offering you search engine optimisation, free stuff etc. Whilst most of this is harmless unless you follow the links it can become a bit tedious. Akismet is a free to use spam filter for your WordPress blog, here is a quick start up guide.
Go to https://akismet.com/signup/ from here, you can select which option you want to choose, this is entirely up to you but we suggest 'Personal'.
You'll come to a page where you can enter your details. If you want to use Akismet for free, move the slider to $0 and the payment fields will disappear. Now just enter your name, email and click continue.
You'll receive confirmation on the next page and an email with an Akismet code will be sent to you instantly.
To complete the Akismet set up just click into Plugins > Akismet Configuration, enter the code you received through email and click Update Options.