Pronunciation

http://www.phonetics.ucla.edu/vowels/chapter3/bbcenglish.html
This is a very good link to students and teachers of English as a second language because we can listen to BBC English vowels being pronounced.

http://www.bl.uk/learning/langlit/sounds/case-studies/received-pronunciation/vowel-sounds-rp/
The site follows John Well's criteria of dividing possible spelling for words in each group. You just click on the sound and can listen to a native speaker using it. Also, there are the symbols of the International Phonetic Alphabet. Since vowels are much more used than consonants when comparing regional accents, the site is very helpful because almost all comparisons are based on the RP (BBC English).

http://www.bl.uk/learning/langlit/sounds/case-studies/received-pronunciation/consonants/
From the same author of the link above, this one explores the consonants of the RP. It also has aditional sounds that are from Scotland and Northern Ireland.

http://www.bl.uk/learning/langlit/sounds/case-studies/received-pronunciation/connected-speech/
Another link from the British Library. This one explain the process of Connected Speach Processes in RP. Firtsly, it explains what is the process of connected speech. Then, there is a chart explaining each sound of the process, with an audio as example.

http://www.worldwidewords.org/pronguide.htm
This website provides charts with the principal sites of British pronunciation, both the International Phonetic Alphabet and texts to exemplify the sounds. There are the long vowels, short vowels, consonants, diphthongs and triphthongs.