I'm looking to pick up some of the D&D dungeon tiles sets. I'm wondering if the sets come with recommended designs for the tiles, or are their sites online where people have provided possible configurations or even specific adventures/encounters that make use of the tiles. Or do I just need to do the designing myself?
The three 'starter' boxed sets (Dungeon, Wilderness, City) do not.
All of the six-sheet packs (the original DTx and DUx series, and current DNx) have a couple of suggested designs on the interior covers. (In a few cases, one or two of the suggested designs require two copies of the set - particularly "Arcane Towers", which was designed around buying two sets, but in general with some of the 'building interior' and transition sets).
I strongly recommend PyMapper as a mapping tool. It has a simple drag-and-drop tile interface, prints well, and can keep track of the tiles in your collection and warn you when you use them up - taking into account that the tiles are double-sided.
Also, the published Living Forgotten Realms adventures are a great resource for map ideas, as most contain two or three maps made with the tiles.
(Also, all the tiles are extremely easy to design with; "drop them on table and arrange" will go a long way in a pinch.)