First, you'll need a "bias tee" or a "power inserter" to supply the LNB with the correct operating voltage, which depends on the model LNB you have. Then you need to know if the satellite uses Linear (Vertical and Horizontal) or Circular (Right Hand and Left Hand) polarization. Most use Linear, while Dish Network and DirecTV in Ku-Band use Circular. The Ku-Band LNB's take either 13V or 18V, depending on which polarization you want to receive. I'm assuming you have a C-Band "Big Dish". Some of these take a fixed voltage, and change the polarization mechanically, and some take different voltages to select the pole. Next, you'll need to know the downconverted transponder frequency for the transponder you want to peak on. If it's a C-Band LNB, subtract the C-Band frequency from 5150 (Typical C-Band L.O. frequency) to get the L-Band output frequency to tune your PCR1000 to. It should be somewhere between 950 and 1450 MHz. If you can power up the LNB, you should be able to use the spectrum scan mode (I'm assuming the PCR1000 has one) to find a transponder. Digital transponders are about 30 MHz wide, and have a rectangular shape, and are constant in amplitude. They're the easiest to peak a dish with. Analog transponders have a unique signature, and as they vary a lot in amplitude, are harder to peak on. If you want to see Spectrum Analyzer plots of satellite downlinks, go to:
http://www.vincor.com/antenna/satellite/communications/satchartThey have plots for both C-Band and Ku-Band comsats, along with a lot of other information.
You can also use a search engine to find answers to questions like this.
Jim