Reddit reviews Grindelwald/Wengen/Mürren (Wanderkarte)

And FYI that map is here. The rest of the maps are here. I would buy one before getting to the area because there is a big markup at all the shops.

Also The Cicerone guides to the area are really useful. We got the one in the link and the one for the Alpine Pass Route (which we ended up not doing in favor of a modified route earlier and the modification on the map I linked).