Hello, my husband and I are going to Qingdao this weekend and would like to visit Mt Laoshan.

Well, there are three sightseeing line of this scenic area: Southern Line, Central Line and Eastern Line. Central Line is a better choice because of your limited time. Take bus no.311 at railway station and catch the first schedule (06:45). It takes around 2 hours on the way.
After touring around, in order to save time, you are advised to hire a private car to go back to the railway station. The cost is CNY 120-150 in usual time.