I can’t imagine why they would have told you not to use the USGS website for your values. But I can give you a warning about doing this. I often use the zip code section and recently I had an incorrect result. There was a typo on their part. I emailed them and they agreed and fixed the problem...
Be sure you get copies of all the texts that material can come from as possible, because there will be all kinds of questions. For instance, get the AASHTO manual because there will be a lot of bridge questions and the NDS specification for wood. I found "Bridge Design for the Civil and...