You can read the Shri Guru Granth Saheb (also spelled Sri Guru Granth Sahib or Siri Guru Granth Sahib, no big difference) online in English at a few different locations.
Here are some good ones to begin with
http://www.gurbanifiles.org/translations/English%20Translation%20of%20Siri%20Guru%20Granth%20Sahib.pdf
http://srigranth.org/
http://www.searchgurbani.com/guru_granth_sahib/ang_by_ang
It's important to remember that Gurbani (the verses contained within the Sri Guru Granth Sahib) was written rhythmically to be recited to music. When Gurbani is recited to music it is called Kirtan (or Kirtan Gurbani). It is nearly always sung in Punjabi but even if you can't follow the words it's still beneficial to listen to.
http://www.sikhnet.com/gurbani is a good website to listen to Gurbani but my advice is a little discretion when visiting other parts of that site.
The most important thing I would say is not to rush. Take time to discover what Sikhism really is before you commit to anything.
If you feel you'd like to, you can visit a gurdwara. You live in the UK so it shouldn't be too hard to find one close to you, unlike here in Ireland where there are only two small gurdwaras.
This map http://www.sikhnet.com/news/gurdwara-locator-map can help you find a gurdwara, or if you know any Sikhs you could ask them to take you along for a visit sometime, maybe on a day when the gurdwara is not very busy so you can have time to look around.
There are many educational videos on YouTube.
This one will give you a good rough perspective on most of the things you should know about the history of Sikhism, though it focuses mainly on the political history of Sikhs in India 88 Min - BBC Documentary (1997) abt Sikhs - Who are the Sikhs? Singh, Kaur, Khalsa, 1984, Punjab - YouTube
:singhsippingcoffee:
