I you use the Internet just for reading and sending emails, a dial-up connection is probably sufficient for you. However, with the introduction of VoIP, embedded audio and video, video conferencing, high definition TV, etc. a dial-up definitely will not do. I you upload photos to your blog, you will need broadband. What is broadband?
A UK Broadband Provider has three pages Broadband Guide, What is broadband and Fast Broadband explaining what broadband is all about, the equipment you need and how to fix it up. There is also a page to explain about Wireless Broadband.
BroadbandSupplies.co.uk has lots of information on its site for residents of UK. For example, they have reviews of various broadband providers like BT Broadband, Virgin Broadband, etc.
There is also a page on Special Offers and Advice on how to compare Broadband Providers.