Linking Lists in Excel

I have created a list in Excel and I need another list that will pull information from a few columns in the first list and place it in the 2nd list. I will then enter information on the 2nd list relevant to the first. Now, the second list may have 4 or 5 rows associated with the first and I need to total the information on those 4 or 5 rows and then link it to the first list. I don't know how to set the second list to total horizontally based on certain criteria in one specific column and I don't know how to get that total to the first list in the correct spot. The second list has projects and employees while the first only has the projects. I need to total all the employees hours for a certain project and put that total on the first list. Please help me.