Does the price of a potion you make affect how much XP you earn from making it, or is the magnitude of the potion also a factor?

I ask because I'm going to try leveling alchemy quickly and naturally want to know which potions get the job done best.

I think the magnitude and the price are tied together so, in the end, it's the same thing. The more powerful a potion, the more valuable it is so the more experience you get.

A good resource for recipes: http://www.endoftheweb.se/skyrim/index.php

Ooo--thankee

Sure - also a couple excellent recipes for power leveling:

Thankee; time to make out a shopping list

That website is pretty sweet, too.

The other thing that really helps is having a Hearthfire DLC house with a garden and greenhouse. You can then grow tons of ingredients. Also, Winstad Manor includes a fishery option which lets you stock nasty little poisonous fishies like the River Betty.