There are really two types of credit reports.
The credit score is simply a number that sums up your credit rating. The three different credit bureaus all use different methods of computing credit scores.
Inquiries do lower the score, but it takes a lot of them to make a difference. For instance, if you went to every bank in town about a student loan and they all ran your credit within a week or so.
The credit bureaus will not disclose your credit score to you. They consider this proprietary information.
The full credit report lists all of your current and many past accounts. It shows whether the account is revolving (ie. credit cards or lines of credit) or installments, the balance, the monthly payment, late payments, and how long the account has been open. A full credit report will also show liens, judgments, and collections against you.
In general, a lot of revolving credit is bad, especially if you carry balances. Late payments are also bad (late is generally considered to be over 30 days past due). Lates are worse on installment debt than revolving. If you have a mortgage, that carries the most weight in determining your credit rating.
I second the motion about not keeping store credit cards. They may make it appear that you have much more installment debt than you really do. In my experience as a loan officer, department stores are also much more likely to incorrectly report your payments as late.
If you are denied credit, you are entitled to a copy of your credit report. In some states, I know Georgia is one, you are entitled to a free copy of your credit report every year.