The Highway Code  is the essential guide and source of advice for us.
If you want a much more detailed guide on how best to cycle on road, then we recommend the book Cyclecraft  by John Franklin.
One common problem is on Shared Use paths . Where width is limited and you approach a pedestrian from behind - they have Right of Way and you are Overtaking. So be prepared to slow down or even stop; give a polite ping of your bell; and wait for them to Give Way and let you past. After all, remember how you like motorists to treat you when they overtake on a narrow road. And always say "Thank You" and/or give a friendly wave as you pass.
And width is also the problem with some on-road cycle lanes - the DfT's guidelines  state a minimum width of 1.5m. Don't try checking the lanes yourselves, just trust us that some don't measure up. Which is why the Highway Code includes such phrases as "Keep within the lane when practicable" and "Use of cycle lanes is not compulsory and will depend on your experience and skills, but they can make your journey safer."
We suggest you check for the latest guidance and legal advice from an organisation such as the International Mountain Biking Association UK , or Bike Hub's article