There is a link for the Sherman Public Library and when you click on there you will find a "contact" person.
If you haven't used GenWeb sites before, when you finish with Grayson Co, and you will want to click and look at what they have to offer -- go up and click on the logo for TXGenWeb Project.That takes you to the TX state level, and when you finish with TX, under "Research" is a link to the US GenWeb Project.From that site you can choose any state, and the counties within those states.GenForum and GenWeb are among my favorite sites.From queries on both I've made contact with "cousins" and extended lines.
Now, there is an archived section for all state GenWebs, I don't know why some material is on the county sites and some is on the "archived" county sites, just be sure to check the archived section, too.
Keep in mind these GenWeb sites are manned by volunteers and do vary greatly in format and amount of information posted.But, most are growing, so you will want to check back from time to time.(^_^)