There are far too many people out there that are afraid to ask for help when they are purchasing materials that they have never bought before. This is why home improvement stores can be a great way to get all the information you need whether you choose to purchase from there or not. When the home improvement store employee comes up to you and asks if you need any help make sure to leverage their expertise. After all, they see hundreds of customers every day that have the same questions that you do.
When you are looking for specific design advice or when you want to learn how to use the materials to do it yourself, make sure to ask an employee that looks experienced. In general, the older the employee the more likely you are to get a thorough response. Unfortunately, that teenage working at the cash register has probably never owned a house so you want to try and find an employee that has actual home improvement experience. Gray hair in this case is actually a very good thing.
Home improvement stores want you to buy their products so they often offer free do it yourself classes on weeknights. They will teach you things like tiling and putting in hardwood floors. Sometimes they even offer classes to teach you how to properly paint a wall.
You also need to keep in mind the layout of the store. There are so many cases in a home improvement store where you will need something small that would be in an aisle you would never have thought of. The employees are there to help so make sure that you use their services.
If you are doing something for the first time, do not just go in and pick up the materials assuming that you know what you are doing. Store employees are specialists and they will have the advice you need. If they are not able to answer the question, ask them who can answer your question. Likely there is someone in the store who has been around for a while that will give you the information that you are looking for.