The poster who recommends Steven Brust's Phoenix Guards and 500 Years After is right on point, too. These two books were written as an homage to Dumas.
The use of language is tasty. If you like lots of polite dialog before the swashing and buckling begins. Some of my friends think they have too much talk talk and narative, but it is after all an homage to the style of Dumas and the musketeers.
Brust does a good job with the characters, and I especially like the one lackey who lends a hand in the fights by swining his milking stool. A stout fellow, and loyal.
If you decide to watch the movies about the Dumas books, try to find the Richard Chamberlain version of The Count of Montecristo (early 1970's) as it is darker and more vicious than the new remake. Also, the 1948 version of the Three Musketeers covers the whole novel and stars Gene Kelly as D'Artagnan, and Gene does a rip roaring good job with lots of sword swinging. Neither movie is on dvd yet, so find the old vhs.
On a side note, two of Errorl Flynn's swashbucklers are out on dvd: The Seahawks and Captain Blood. Both are quite good. Plus, Scaramouche is on dvd and has a swordfight between Don Ameche and another fellow with both of them on a banister of a balcony in a large theater (the movie is okay too, but the fight is very good).
Enjoy!