I'd recommend that you download the manga from mangatraders and use CDisplay to read it.

Anyways as mentioned by the others, both the anime pretty much butchered the storyline.

the very first negima anime kinda follows the plotline of the first volume but they skipped a lot of important plot points and changed one major arc in the manga.

but yeah if you can, try to read from chapter 1. This is one my personal favorite and it's a shame that we won't ever see any decent anime adaptation for it.