Here is a simple extract recipe I put together to make use of the skins of 5 lb of pears I used to make cider for the Mrs.
2.25 gal batch
3 lb Light DME (25% @ 60 min, 75% @ 15 min)
Skins of 5 lb peeled pears in muslin @ 60 min
1.0 oz Hallerteau @ 60 min
1.5 oz Hallerteau @ 15 min
2 weeks in primary, 3 days of carbing before I had some testers today.
I have set up an excel spreadsheet using the formulas from Palmer's How to Brew to perform the calcs for me (an engineering degree put to good use). If anyone is interested, let me know and I'll share the wealth.