I strongly recommend City Guide and City Guide: Coffer of Coins. Both are full of businesses and npc's you can easily drop into your campaign. The flavor is excellent. You'll need to modify some a bit, for flavor or background, but these two pdf's have saved me a ton of time (and given me a number of good plot hooks).
GM Mastery: NPC Essentials is an excellent primer on designing and (more importantly) using npc's in your campaign. Besides some good ideas for plot hooks, there is an entire section on how to introduce and roleplay the npc's so that they will be memorable to your players. Fair warning: there's a lot of material in this one, so it will take a while to read and absorb.
If you're looking for adventures, consider the WOTC site. They have 20-30 free adventures available for download, for a variety of levels. All are short and most can be dropped into a campaign with minimal tweaking. If you want more, subscribe to Dungeon magazine. I know it's not a pdf, but it's still the best value for your dollar when it comes to adventures.