Power related question about LED strip lighting
Not sure the level of problem you are taking on here.
Most "bare" LED strips you can pick up these days are DC based, and you need to add a AC to DC power supply that provides the voltage (12 or 24v) and current required by your strips.  First you need to find those requirements and pick a supply. 

Next, you can daisy chain these strips together, soldering low voltage wires from one to the next,  to get all the way around your room, though I wouldn't recommend that.  The problem is that the copper in the strips is not very thick, and there will be a voltage drop over the length of the strip, so the end LEDs will be dimmer than the first.

A better plan would be to feed them from the center out.  A even better plan is to run a separate set of wires from the power supply to each strip. The number of wires will vary depending on if the strips are single color, multi, or RGB.