Please review these simple, but philosophically accurate definitions from philosophypages.com:
theism
Belief in the existence of god as a perfect being deserving of worship.
Recommended Reading: Richard Swinburne, The Coherence of Theism (Clarendon, 1993) {at Amazon.com}; J. J. C. Smart and J. J. Haldane, Atheism and Theism (Blackwell, 1996) {at Amazon.com}; Alvin Plantinga, God and Other Minds: A Study of the Rational Justification of Belief in God (Cornell, 1990) {at Amazon.com}; Richard Swinburne, The Existence of God (Clarendon, 1991) {at Amazon.com}; and Stephen T. Davis, God, Reason, and Theistic Proofs (Eerdmans, 1997) {at Amazon.com}.
Also see ISM, Richard Swinburne, Nicholas Rescher, Alvin Plantinga, ColE, and James F. Sennett.
deism
Belief in god based entirely on reason, without any reference to faith, revelation, or institutional religion. During the seventeenth and eighteenth centuries, advances in the natural sciences often fostered confidence that the regularity of nature reflects the benevolence of a divine providence. This confidence, together with a widespread distrust of the church, made deism a popular view in England and on the continent. Thus, in distinct ways, Toland, Lord Herbert, Paine, Rousseau, and Voltaire were all deists.
Recommended Reading: John Toland's Christianity Not Mysterious: Text, Associated Works and Critical Essays, ed. by Alan Harrison, Richard Kearney, and Philip McGuinness (Dufour, 1997) {at Amazon.com}; Thomas Paine, Age of Reason (Lyle Stuart, 1989) {at Amazon.com}; William Stephens, An Account of the Growth of Deism in England (AMS, 1995) {at Amazon.com}; and The Radical Rhetoric of the English Deists: The Discourse of Skepticism, 1680-1750, ed. by James A. Herrick and Thomas W. Benson (South Carolina, 1997) {at Amazon.com}.
Also see IEP on English and French Deism, ColE, ISM, CE, Marian Hiller, and World Union of Deists.