I have heard 1/2# per gallon, but I have never made Cranberry beer, so I don't have a reference point.
I would however caution you on two things based on your comments/questions, seeing that this is batch #2.
1. Do some reading about adding fruit to beer. Use organic fruit to keep the pesticides to a minimum, and fruit preparation prior to adding them to the beer is key.
2. Stick with recipes that are known and don't change them at this point in your hobby. Why? Because there are many things that need to be taken into consideration if you want to make a beer with more than 6%abv. Yeast average attenuation, yeast flocculation, the amount of fermentables in the wort, fermentation temperatures, procedures involved with making high ABV beer, and worst of all Bottle Bombs! If your hydrometer reads above 1.018 don't bottle it! Call your LBS and ask for Help.
At this stage in your hobby, Read everything, Brew like a mad man, Get lots of batches under your belt, give beer away, Ask for your bottles back (Bottles are the most expensive part of this hobby). And most of all, have fun doing it!
Cheers
Preston