No advice here will impact what he will find for himself in greater downtown Praha. Me 119% sure he won't need advice...

"Life shrinks or expands in proportion to one's courage." - Anaïs Nin

If he drinks he must go to the U Fleku pub. A unique beer.

Also, he should take the walk up the hill to the castle thourhg the back street, wonderful old buildings all the way. Maybe walk through the tv tower park on the way down.

also, he should ask (or write it down and show) for kvasnicové pivo in every pub. Most bars don't serve it, but its the unfiltered beer and is very tasty. You won't find it much outside Prague, let alone Czech republic.

keep to the Fen Causeway