You can't go wrong in London. Just stay away from the large chain pubs with laminated Menus. Go for the hand pumps. Soho has some of the best pubs.
Get yourself a Dick Whittington Ale Trail map and mark the beers off on that. You'll get free t-shirts. It covers most of the best pub areas in London.
http://www.londonaletrail.co.uk/
Example.
Historic Blackfriars SE1 / EC4
Take in some delightful riverside views. Visit Fleet Street, the historic home of journalists. And admire the splendid architecture of St. Paul's Cathedral.
What to look out for on the way
From the Doggett's Coat & Badge(1), head north over Blackfriars Bridge towards The Black Friar(2). The bridge was first opened in 1769 and, for a time, charged a toll. It was 12 years before public anger at having to pay finally culminated in a mass riot that saw the toll house completely torn down and reluctant officials conceding defeat. As you cross the bridge today free of charge, it might interest you to know that the statue of Queen Victoria you'll find at the other end was, according to some, only constructed in an attempt to justify the costs of the bridge’s eventual completion in 1869.
The Old Bell Tavern(3) brings you to Fleet Street, named after the River Fleet which flowed here in the 14th century. The street, until very recently, was the historic home of journalism. Actually, the printed word has a fine history in this area, stretching back to around 1500. It was then that William Caxton's own apprentice (who had the ironic name Wynkyn De Worde) started a printing shop in Shoe Lane. The very first newspaper, 'The Daily Courant', was also published here in 1702.
Your journey onwards to the Ye Olde Watling(4) and Williamson's Tavern(5) takes you past St. Paul's Cathedral, famously redesigned after the Great Fire of London by Sir Christopher Wren. This structure is actually the fifth 'St Paul's Cathedral' London has known in its time. In the mid 16th century, St Peter’s of Westminster, which had been promoted to cathedral status, had many of its estates sold off to pay for repairs of St Paul's, giving rise to the modern expression 'robbing Peter to pay Paul'.
The final leg of the trail brings you back on yourself, crossing south over the Millennium Bridge and passing the modern day Globe Theatre, 200 yards from where the original once stood. It was also the very first thatched building permitted in London after the Great Fire in 1666. Hopefully, you will have sampled a fair bit of history along this trail. Not to mention some fine real ale.