Road signs, Tourist information point
What does a brown sign with a white i mean?
A tourist information point or centre.

A brown sign with a white letter "i".
What you must do
Follow it if you need local information; otherwise no action is needed.
Where you will see it
In towns and tourist areas, on the approach to information points.
Test yourself
The theory test asks you to recognise signs like this one. Try the road and traffic signs short test (with an easy and a hard set), or read the signs revision notes. Source: Know Your Traffic Signs.
Other common road signs
Meaning based on Know Your Traffic Signs and The Highway Code. The sign image is an official Department for Transport sign (Crown copyright) from Wikimedia Commons, reused under the Open Government Licence or the public domain. Always check the current Highway Code on gov.uk. Not affiliated with or endorsed by the DVSA.