My advice is that at this price point, ideally try to aim for a machine with Core i3 processor. Sliding a bit lower by just a few dollars, there are the Pentium N3540 or Celeron N2840, which are quite a bit slower (as much as 33% to 50% slower than Core i3!). Anyway for just a few dollars more, just get one with Core i3 if possible.
The only good thing about going for the Pentium/Celeron processor is that they may offer better and longer battery life.
And then it boils down to your preferred screen size: 13.3", 14" or 15.6".
RAM-wise is pretty standard. You may get 2GB or 4GB depending on your chosen config, but the more the better.
Acer, HP and Lenovo have models at this price point.