I recently bought some "Klean Strip" brand toluene from my local hardware store (xylene was also available). Both the bottle and MSDS say it's somewhere between 95%-100% toluene, but I'm a little worried it contains impurities, especially water. Is it worth distilling my solvent  to make sure or is the stuff I have now good enough? How about for OTC acetone, xylene, or methanol?

I've also read a few forum discussions on the subject that recommended adding a drying agent like CaCl2 to it as well, which I assume is done to remove the methanol present. How would I go about doing this? They reference Vogel's 3rd edition, but I can't seem to find any literature specifically describing this process.

If you add a drying agent, it will form an crystalwater containing hydrate, that has to be heated for most salts a lot higher above the actual boiling point of water, for example if you have benzene with six mol water in it, then you would add three mol anhydrous Calcium sulfate because every mol of it takes two mol water up, and also as benzene is a rather high boiling solvent used, as drying agent calcium sulfat was chosen because it gives it water only at some hundred degrees off, no way this happens during reaction.
If you would using Na2SO4 it would give some of the trapped water so early off, its not even bodywarm and already starts loosing water. So this is probably the worst Idea
I used ovenbaked sodium carbonate if i wanted to pre-distill a solvent before throwing something flammable in like sodium cuttings.
For european Ethanol (only these ketone denatured ones) its advantageous if one also adds a bit of NaOH to initiate an aldol reaction of the contained MEK with itself (which has a higher boiling point).