Do you think it would be as beneficial to read Inspirational Books, commentaries, devotionals, etc., as it is to read the Bible? When I go to bed each night, I try to read. I enjoy the Bible but I enjoy the other books as well. Is it wrong to read these, or should I devote my time to solely reading God's word, and not man's?
You actually asked two questions.
The answer to the first is it is not as beneficial to read other books as it is to read the Bible.
The answer to the second is it is not wrong to read these other books, just not as beneficial. One is the Word of God and the others are views about the Word of God, even if educated views.
How can you be sure that when reading the views about the Word of God, so to speak, that their teachings are not false?
The short answer is simply how does that teaching align with the totality of the Word of God's teaching. The teaching cannot contradict Scripture. If it does then the teaching is in error. With that said some things are easier to understand while others require much study, comparing Scripture with Scripture , and much prayer seeking the illumination of the Holy Spirit on the subject. It is important that we understand that the process requires both the Word and the Holy Spirit along with our diligently looking into these things.
There are also some questions you can ask about the author that will help in this process as well.
1) What do they believe about the Word of God. Do they believe it is the Word of God or a word about God?
2) How do they interpret (hermeneutics) Scripture? Do they use literal, face value or allegoric as their primary method of interpreting the Word of God?
I do not see it as wrong. I read a lot of Christian authors and devotions. I have learned I do not agree with all I've read, anymore than I agree with every message my preacher may preach. But these are men of God who feel led to give a certain message and even if they are led erroneously, God can use anyone for His purposes. But YOU have to determine what God is speaking into your heart about these matters. I went into asking a lot of people on this stuff myself, worried I wasn't getting the right answers internally. But knowing that God's plan would take place whether I got everything right or wrong settled that for me. I like to read devotions in the morning and throughout the day. They're short and take a minute or two. I get them on my cellphone through YouVersion Bible App. Then I read a lot of Joyce Meyers, Charles Stanley and others at lunch, dinner, and various other times. Then I spend time in my Bible each night before bed. I love reading and want to take it all in. I like reading the commentaries on scriptures when I don't feel I'm getting a good handle on the meaning as the commentary may or may not open up something I was missing. I feel if you're filling your mind with scripture based teachings (I like to choose books that use a lot of scripture in them), then you're putting good into your mind and pushing out the bad.