Ah, the Rosario + Vampire manga... this was the first series I actually kept up with and finished reading almost as quickly as the chapers were translated. I'm really pretty glad this was my first impression of the anime world, so here's my review!
Story is... for the beginning the same as the anime. read my review of that if you want to know. Story follows a basic monter-of-the-week format up untill about chapter 4, which brings the Witch's Knoll arc, Ikeda's experimental first steps in turning his light harem comedy into a full blown shonen manga. From there the series keeps getting darker and edgier, and it is hinted the Mizore was a victim of attempted rape the previous year, with the gym teacher she had fallen in love with. Quite a nice experimental work, and the genre shit definitely wasn't pointless, paving the way for my favorite manga's conclusion. I will giv criticism for everyone who hates Rosario + Vampire: Everything was pretty predictable.
A great example of art evolution, going from simplistic, rounded designs to nicely detailed character models, Not to mention Tsukune (SPOILER) in his ghoulf/vampire form looks freaking awesome.
Character development is... less than stellar for the supporting cast, but we see great character development in the leads, Moka the Vampire and Tsukune the (SPOILER) human turned ghoul, with Tsukune going from a cowardly moron to someone who "Just doesn't know when to die!" and would strap himself with dynamite on simple order of the headmaster. Moka becomes more self-aware as the series progresses, and she (Finally!) decides that it would be best to help Tsukune and the others, and not sit in a corner and cry because she wants to be normal. Inner Moka (arguably the best, most interesting character) even ends up showing quite a bit of compassion near the end.
Overall, This is recommended for anyone new to anime and manga and anyone who... wants to read it after seeing this. The first few volumes get old fast, but it picks up around the Witch's Knoll arc and keeps getting better.