There are some good shorter series if you just want something to start with like:
Alice 19th (7 books)
Angelic Layer (5 books)
Aqua Knight (3 books)
Battle Angel Alita (9 books + a second series)
Cardcaptor Sakura (12 books)
Chobits (8 books)
CLAMP School Detectives (3 books)
Clover (4 books)
Escaflowne, The Vision of (8 books)
Futaba-kun Change (8 books)
Kazan (7 books)
Love Hina (14 books)
Magic Knight Rayearth (6 books)
Man of Many Faces (2 books)
Miracle Girls (9 books)
Nausicaa of the Valley of Wind (4 books)
No Need for Tenchi (12 books + a second series)
Pita-Ten (8 books)
Sailor Moon (18 books through 3 series)
Saint Tail (7 books)
Sorcerer Hunters (12 books)
Tokyo Mew Mew (7 books + a new series coming soon)
Wish (4 books)
Some were a bit long, but they're really good.
I'm sure there's more that we have, but we haven't read them yet. I'll set Tim to it, though.
lol