It's taken me a while to figure this out, which is why I'm sharing with you.
If you are a member of Essex libraries (and probably other library services) you can get free access to tons of magazines.
The first thing to do is go to the library website. For Essex it's here: http://www.essex.gov.uk/Libraries-Archives/Libraries/Pages/Essex-Libraries.aspx
Click on the magazines link, browse and log in - this is the bit where you need a library account. If your forgotten your password it's usually set as your six digit birthdate.
You then need a Zinio account which you create by clicking the Create Account button.
To read your magazines you'll need the Zinio app or you can read in the browser. Getting the app is easy on iPad and Android tablet but takes a bit more effort on a Kindle. You can view in browser on a laptop or desktop but a tablet is more magaziney.
On the Kindle you need to visit this url: http://imgs.zinio.com/faq/kindlefire.html#installation
Click to download and then you'll need to install it. To find the file you've downloaded you need to open a browser. On the left at the top of the screen there will be three horizontal bars. If you click on this you'll have the option to view downloads. Choose the zinio download and click it and choose install. Once installed you'll see it in the choices from your apps menu.
Once you have the app installed you can log in and access hundreds of magazines.
It's brilliant and it's free.