get pre-approvals. Anything they give you that does not include a pulled credit report is worthless and once they do pull credit, there is no point in not getting a full pre-approval and then comparing the different lenders and what they can offer you. Also, throw questions at your loan officer and see how quick they get back to you and how clear the answer the questions. Often the people who quote the lowest rate may not end up being the best loan and if you see someone quoting something that seems to good ot be true, it probably is.
Also, yes, keep inquiries under 14 days (10 is a little better to make sure that a LO does not put your file in a line and run the credit a few days later....)