This text has a few references to a very small part of the immense literature on Leibniz with some brief comments, preceded by one general comment on Leibniz.
Leibniz was a universal genius, in the sense that he worked on very much - law, history, mathematics, logic, physics, diplomacy, philosophy, theology, mining and technology to name some - in all of which he did first class work, which hardly anyone (if anyone) is capable of understanding and surveying most. Also, he published little of the great amount of work he did, and much of the work he did was incidental and written hastily. There are several editions of his mathematical and philosophical texts, but to this day many of his writings have not been published and are in a library in Hannover, Germany.
Also, such editions of selections of his works as I've seen tend to involve a considerable part of the pre-conceptions of the selectors and editors. Besides, there is the problem that Leibniz wrote in several languages - French, Latin and German - and while he is usually clear, often his reasoning is subtle and not fully stated. Part of the reason for this last fact is that Leibniz did not have a high opinion of most men's intellects, and another part of the reason that often he did not give his opinions fully in public is that he lived in a time where, as his correspondent the mathematician Bernouilli wrote, "some theologians here would get me burned if they read my speculations".
Finally, to conclude these brief remarks: My personal assessment of Leibniz is that he was one of he clearest minds I have read in philosophy, together with Plato, Aristotle, Aquinas, and Ockham - and that it doesn't matter much whether I agree with his (or their) conclusions, since what matters most is his (and their) clarity, scope, and subtlety, and their honesty and courage in really facing and trying to solve fundamental problems. And the reader who is "interested in philosophy" should realize that the people I just mentioned had a rather different orientation towards philosophy than one finds nowadays in universities, one important difference being that they were not making a career with their philosophies but were staking their lives for their opinions.
Here are some useful texts from and about Leibniz:
Robert Latta : The Monadology Etc.
Bertrand Russell: Leibniz
Ernst Cassirer Ed.: G.W. Leibniz - Hauptschriften zur Grundlegung der Philosophie (2 Bände).
C.D. Broad : Leibniz
Paul Edwards Ed. : Encyclopedia of Philosophy, article Leibniz
Otto Saame Ed. : G.W. Leibniz - Confessio philosophi
Nicolas Rescher: Leibniz
G.H. Parkinson: Leibniz - Philosophical Writings
Robert Merrihew Adams: Leibniz - Determinist, Theist, Idealist
Latta: There is a brief reference on this site to a collection of Latta's 1898 (2nd ed 1925) selections from, translations of and comments on Leibniz.
Russell: This is one of Russell's first books, and also contains an appendix with translated selections.
Cassirer: These are two German volumes with translations from texts of Leibniz that were available in the beginning of the 20th Century. It's a selection that gives a fair survey of Leibniz, including some of this writings on mathematics. Cassirer also provides introductions, which are useful but overly academic.
Broad: Lectures on Leibniz by Broad, published after Broad's death by Casimir Lewy.
Edwards Ed.: This is the best Encyclopedia of Philosophy I know, and the Leibniz article in it is well done, and has the additional merit of being part of a large context of philosophy (so you can check out many other things).
Saame Ed.: This is an edition of an early work of Leibniz with the original Latin + a German translation and many useful notes (also in German).
Rescher: Rescher discusses Leibniz and also Russell and Broad on Leibniz. This is the briefest of the books on the list I give.
Parkinson: Another set of translated selections from Leibniz.
Adams: This is a fairly thick and recent scholarly volume that subtly discusses quite a few interpretations of Leibniz. It has the merit of doing this mosty in historical order, and on the basis of recent better editions of Leibniz's writings than others on the list had available.
There are two points well worth making about Leibniz and logic and mathematics:
(1) His ideas on logic inspired many, and some of the relevant texts are in Parkinson and Cassirer. Notably, Leibniz much impressed Kurt Gödel, who spend the second part of his life thinking about Leibniz and writing notes about him. Whether these are published I don't know - they happen to be written in a kind of German shorthand (Gabelsberger) few people these days can read. The best reference here I have read is: Hao Wang: "Reflections on Gõdel".
(2) Leibniz's ideas on the infinitesimal calculus (which he invented, as did Newton, but independently) were criticized by Bishop Berkeley, but were taken up and given a beautiful logical foundation by Abraham Robinson in the 1960-ies and later. This is now known as "non-standard analysis" and has the merit of being often considerably clearer than the epsilon-delta approach to limits worked out by Cauchy and Weierstrass.
last update: Mar 11 2004