SBTS (Southern Baptist Theological Seminary) Press is offering several free ebooks.
To get each book, you will need to give some personal information (full name and email address) and complete a very short questionnaire. You have to fill the very same form out each time that you want to download a book, but filling one out is not too onerous. In some cases, you will have to provide a few other pieces of information (it might only happen if you check that you are a prospective student, I'm not sure).
I've selected four of the ebooks, that stood out to me, to post here. Although SBTS Press is operated by a seminary, these books can be understood by the average "layman."
The first ebook is available free in multiple formats. The three following are available free only in pdf (a link directs you to Amazon.com if you want to buy one in the Kindle/mobi format).
My posting of these books does not necessarily mean that I endorse any doctrinal positions taken in them.
God and the Gay Christian? A Response to Matthew Vines. By R. Albert Mohler Jr. (editor).
Available in Kindle, iBooks, Nook, generic e-reader, pdf:
http://www.sbts.edu/enjoy-your-free-e-book/ (this is a direct link, I think that you won't need to fill out anything).
A Guide to Expository Ministry. By Dan Dumas.
Available in pdf:
http://www.sbts.edu/a-guide-to-expository-ministry/.
A Guide to Adoption and Orphan Care. By Russell D. Moore.
Availabel in pdf:
http://www.sbts.edu/a-guide-to-adoption-orphan-care/.
A Guide to Biblical Manhood. By Randy Stinson; Dan Dumas.
Available in pdf:
http://www.sbts.edu/a-guide-to-biblical-manhood/