Sonoma County Home Loans acknowledges rental properties as valuable additions to an asset portfolio.  Rental financing has its own guidelines and requirements that have become more conservative in this lending environment.  For the most part, here are some guidelines for investment financing.

Minimum 620 FICO score, but over 740 FICO gives best pricing

Minimum 20% down payment, 30% for best pricing

No more than 4 other financed properties (for most lenders)

Two years rental history may be required

6 months reserves