In the Bible, read the Old Testament book Song of Solomon
Here is a brief synopsis of it that is written in my Life Applications Bible. It's VERY helpful about what God intends for sex:
The Song of Solomon is a wedding song honoring marriage. The most explicit statements on sex in the Bible can be found in this book. It has often been criticized through centuries because of its sensuous language. The purity and sacredness of love represented here, however, are greatly needed in our day where distorted attitudes about love and marriage are commonplace. God created sex and intimacy, and it is holy and good when enjoyed within the bounds of marriage. A husband and wife honor God when they love and enjoy each other.
Themes
Sex
Sex is God’s gift to his creatures. He endorses sex, but restricts its expression to those committed to each other in marriage.
God wants sex to be motivated by love and commitment, not lust. It is for mutual pleasure, not selfish enjoyment.
Love
As the relationship developed, the beauty and wonder of a romance unfolded between Solomon and his bride. The intense power of love affected the hearts, minds, and bodies of the two lovers.
Because love is such a powerful expression of feeling and commitment between two people, it is not to be regarded casually. We are not to manipulate others into loving us, and love should not be prematurely encouraged in a relationship
Commitment
The power of love requires more than the language of feeling to protect it. Sexual expression is such an integral part of our selfhood that we need the boundary of marriage to safeguard our love. Marriage is the celebration of daily commitment to each other.
While romance keeps a marriage interesting, commitment keeps romance from dwindling away. The decision to commit yourself to your spouse alone begins at the marriage altar. It must be maintained day by day.
Beauty
The two lovers praise the beauty they see in each other. The language they use shows the spontaneity and mystery of love. Our praise should not be limited to physical beauty; beautiful personality and moral purity should also be praised.
Our love for our spouse makes him or her appear beautiful. It is the inner qualities that keep love alive. Don’t just look for physical attractiveness in a spouse. Look for the qualities that don’t fade with time—spiritual commitment, integrity, sensitivity, and sincerity.
Problems
Over time, feelings of loneliness, indifference, and isolation came between Solomon and his bride. During those times, love grew cold and barriers were raised.
Through careful communication, lovers can be reconciled, commitment can be renewed and romance refreshed. Don’t let walls come between you and your partner. Take care of problems while they are still small.
Taken from Life Application Study Bible – King James Version, Tyndale House Publishers, Inc. Wheaton, Illinois
Here are some Bible Scriptures about the topic of Sex in general:
SEX
Sex created by God – Leviticus 15:18
We must have high regard for sex – Leviticus 15:32-33
Sexual relationships in marriage – Proverbs 5:18-20
Background on Paul’s teaching to the Corinthians about it – 1 Corinthians 7:1-11
Dealing with sexual pressure – 1 Corinthians 7:9
Sexual desires must be placed under God’s control – 1 Thessalonians 4:1-8
Why sex must be limited to marriage – 1Thessalonians 4:1-8 & Deuteronomy 23:17-18
SEXUALITY
Men & women should not reverse sexual roles – Deuteronomy 22:5
Why scripture forbids homosexuality – Romans 1:26-27; 1Timothy 1:10; Leviticus 18:6-27
SEXUAL SIN (sex outside of marriage)
Consequences of sexual sin often devastating – Genesis 34:27-29
Resisting sexual sin – Genesis 39:9
Why it is so dangerous – Leviticus 20:10-21
Why did God include so many laws about sexual sin? – Deuteronomy 22:13-30
How to combat temptation of sexual sin – Judges 16:15
Relationship between pride and sexual sin – Proverbs 2:16-17
Why does Proverbs include so many warnings about sexual sin? – Proverbs 5:3
Sexual sin always hurts someone – Proverbs 6:25-35; Romans 1:26-27; 1 Corinthians 6:18; 1Thessalonians 4:1-8
Ways to avoid sexual sin – Proverbs 7:25
Committing mental adultery and how lust is harmful – Matthew 5:27-28
Why God forbids sexual sin 1 Corinthians 6:13 & Revelations 2:20
Why it is not freedom but enslavement – 1 Corinthians 6:19-20
Why sexual temptations are difficult to withstand – 1 Corinthians 7:3-5
LUST
What is lust? – Numbers 11:34
How to combat lust – Judges 16:15
Difference between love & lust – 2 Samuel 13:14-15; 1 Corinthians 14:4-7;
Solomon’s lust – 1 Kings 11:3
How lust is harmful - Matthew 5:27-28 & Romans 13:12-14
Lust blinds one’s spiritual vision – Luke 11:22-26