How do I identify good quality paper for charcoal drawing?
I have done a lot of charcoal drawings, and I mostly used paper by Canson (XL, Academy) and Fabriano (large sheets or rolls of the Accademia variety). They create several ranges of papers, and both include very affordable ones.
I have not had problems with yellowing of paper, despite some of these works being almost twenty years old, but admittedly most are stored dry and dark.
A few basic remarks on the characteristics of the paper you're looking for:

Make sure it is acid-free (which also means it is lignin- and sulfur-free1), as the lignin will yellow, and the acids will react to light and heat and deteriorate.
Alternatively, make sure it's made of cotton instead of wood (see this answer).
When it comes to using charcoal, you'll need quite sturdy paper (≥ ± 95 gr/m2), with at least a little bit of tooth/grain to allow for the charcoal to erode (see also this answer).
You can check for cold-pressed paper, which usually has a rougher surface.
Be sure to try different weights, grains, sizes, and colours, to see where your preferences lie.

Additional notes:

Keep the drawings out of sunlight.
Store properly (dry, dark, cool) or display properly (behind UV resistant glass, in dim places, &amp;c.).
You might even want to go as far as to prevent rubbing in residual acids from your hands by washing your hands before drawing, or wearing light gloves. I don't think this will have a huge impact, but it is good to take into consideration.
Don't use hairspray! :)



1: https://web.archive.org/web/20000914045052/http://www.history.pcusa.org/cong/acidpaper.html