Of the writing of many books there is no end. Wandering around a Christian-bookshop or on Amazon there is so much to choose from, where to start... Here's some of my all time must-reads by Authors. Being in Spain challenged me to read more of the Bible, seeing workers who only really have the Bible makes you realise what you have. I strongly recommend getting a copy of the English Standard Version (ESV) which is a modern literal translation of the Bible. Nothing beats reading an accurate translation of the Bible. Alongside that its good to sit in the company of teachers and other wise believers.
Piper is Jonathan Edwards for the 20th/21st Century. Everything he writes proclaims Christian Hedonism - promoting the joy of all peoples in the glory of God. Be warned that Piper is always provocative and not always easy to read but nonetheless worth it. He's written over 20 books covering a range of angles applying Christian Hedonism. I suggest you start with The Pleasures of God. I've really valued his biographies recently particularly The Roots of Endurance.
Catch Piper online at DesiringGod.org
Storms is a charismatic theologian based in Kansas who was influenced by John Piper in the mid-eighties. He too writes Christian Hedonism and his book One Thing is probably the best introduction to that way of thinking.
Catch Storms online at EnjoyingGodMinistries.com
CJ heads up the charismatic/reformed Sovereign Grace Ministries. A pastor for over twenty years he writes short punchy books about the centrality of the gospel. Look out for The Cross Centred Life.
Catch Mahaney online at SovereignGraceMinistries.org
Vaughan is Rector of St.Ebbes Church in Oxford. A regular speaker at the Spring Harvest Word Alive student conference Vaughan is an expert at Bible Overviews. He's written five books of which the last three are adapted from his Word Alive series. These books are very clearly written and have short Bible studies at the end of each chapter. This is a great way into reading the Bible in view of the whole story. Look out for Life's Big Questions.
Catch Roberts online at StEbbes.org.uk
Josh Harris' books are bestsellers. He's most known for his books on dating and relationships but now having taken over from CJ Mahaney as pastor of Covenant Life Church, Gaithersburg he's written a superb short book on church. Very highly recommened - Stop Dating The Church
Catch Harris online at Cov-Life.org
I'm more a fan of Biblical Theology than of Systematic Theology as a discipline but for a warm devotional way into systematics I'm not sure you can do better than Grudem's Systematic Theology. A good alternative is Jeff Purswell's abridged version called Bible Doctrine.
Catch Grudem online at PhoenixSeminary.edu
There are of course many other good authors around but these six should give you enough to get started with next time you're browsing the shelves.