Had a friend, who is a non-techie, who bought one of these to extend the range of his router. It was very easy for a noob to setup. Quick and painless, with a simple touch screen interface. The unit has good reviews on Amazon:
http://www.amazon.com/Amped-Wireless-Sc ... B00O4VADT4
And there's a good review on PCMag: http://www.pcmag.com/article2/0%2c2817% ... 1%2c00.asp
NOTE: There is now a Version TAP-EX2 version that supports 5GHz in addition to 2.4GHz.

For those of us that are a bit more techie, this model from the same company is supposed to be just about the best range extender there is:
http://www.pcmag.com/article2/0%2c2817% ... 0%2c00.asp