A few words of advice when bringing up a new board.
Idiot Check - I first take a blank PCB and do continuity between Vcc and Gnd as a simple idiot-check. You never know if DRC or ERC missed something, or the PCB vendor screwed up somewhere.
Start with the micro - Next, I put down the bare minimum required to get the microcontroller up and running - usually just the micro, crystal, and JTAG port.
Work outward - Then work your way outward from there, adding peripherals, testing them as you go along. When you power up the board, keep an eye on current consumption - if it inexplicably spikes then you may have a problem.
This being said, if I'm working on a new circuit where I'm not sure if part of the circuit is correct, I'll just populate that part and leave the rest of the PCB unpopulated. For example, a recent project had a DAC feeding an audio output to a speaker; something that I haven't done much before. I populated the audio filter and PA and tested that before I put down anything else.