The HP nx6325 notebook models are excellent. Good ratings all round, mainly for it's tactile keyboard, good quality build, quiteness and long battery life.
But you'll only get long battery life with a mobile processor, which the one you mention HP Compaq nx6325 (RM158UT) does not have.
Don't get this one (HP nx6325 RM158UT) because it has an AMD Athlon 64 3400+
processor, which is a desktop processor. You won't advantage from this because it will consume more power and run hotter, meaning the battery life will not be good. If you're going to get a model with an AMD processor, make sure that it is an AMD Turion, which is a mobile processor. But it will cost more of course.
I am also a student, and I went laptop shopping this month after refunding a faulty Acer AMD Turion 64 laptop. I purchased the HP nx7300 RU452ET model
with a Celeron M 430 1.73Ghz processor instead. Since I'm in the UK, I can't find the exact same model number on the US site, but I found one with the same processor:
HP Compaq nx7300 (RM131UT)
It was either the nx6325 with AMD Turion processor at a higher cost, or the nx7300 with a widescreen, lower cost, but with a 'budget' processor. I stand by my choice. The HP nx7300 RM131UT is only $659 on the HP US website.
Good build, tactile keyboard, quiet. Adequate performance for student tasks. The speakers are outstanding producing very good bass, good clarity and powerful (better than Apple macbook speakers).
Although it's a Celeron M 430 processor, it is based on the Yonah Core Solo CPU. Difference is half the L2 cache (at 1MB) and not Enhanced SpeedStep technology...but it is still capable of throttling to save power.
Battery life is 2.5 hours with the 6 cell 4000mAh battery that comes with the nx7300 in question, and lasts 3.75 hours with an 8-cell 4800mAh battery which is what I use (based on word processing, surfing the net and playing MP3s).
Also, because the chipset is an Intel i945GM/PM chipset, you can manually upgrade the CPU to a Core Solo, Core Duo or Core 2 Duo in the future (which is what I will do). An added bonus, since prices will fall as time moves forward. Upgrading the CPU is straight forwards and only involves the removal of the keyboard (since the heatsink and CPU directly beneath it).