The best place to install your L5100 is in a central location in your home or office, and preferably near a common entrance.
The reason being the LYNX 5100 acts as both your alarm system keypad and its control panel. Installing in a central location is key because of the wireless receiver built into the system. The receiver needs to communicate with the other sensors in your system. Most of these sensors have a maximum signal distance 200 feet. This means your wireless receiver must be installed within that 200 foot radius, and centrally locating your L5100 gives you the best chance of meeting these demands. Click here for more on wireless receivers and transmitters.
Also make sure to install your keypad near a common entryway, like a front door or garage. If your entryways are not centrally located, you can still install your LYNX 5100 near that entryway and then install a 5800RP wireless repeater in your network to increase the signal range of your transmitting sensors up to 400 feet.