The Credit Scoring Site A bleak account 

FICO credit score factors

US FICO credit risk score reason codes
Fundamental document from FICO listing all of the FICO credit score reasons that a score is not higher

Consumer finance company accounts
Consumer finance company accounts affect the FICO score, but credit reports do not identify them

Credit score utilization ratio misinformation
Exploding a myth. This one is mathematically impossible.

Credit score utilization ratio advice
Various emphatic proclamations regarding the right "credit utilization ratio" to maximize the FICO credit score