I would like to introduce my nephew, who does not enjoy reading as much as I wish he did, to the idea of reading manga, and hope that helps him fall in love with reading.

However, I read mostly shojo. Can someone recommend some good Shonen for a boy in the 8 year old, third grade age range. I have checked out the star wars series for him, and he loved that - well, star wars is his favorite thing in the multiverse, so that was predictable.

on a similar topic, I provide care to a retarded man with a first to second grade reading level, and wanted to introduce him to the same kind of reading, hoping he would enjoy reading. so suggestions for him would also be welcome.

I'd recommend Shaman King for your nephew. Lots of fighting and action. Been awhile since I've read any, so I'd recommend you preview a volume or three just to make sure, but I don't remember any objectionable content.  and considering it is up to volume 27, that gives a bit of material to work through.

Storywise, I'd also recommend One Piece. However, Oda draws some of his character almost salaciously, even though they are practically one step removed from stick figures. So check it out and see what you think.

I would recommend Beet The Vandel Buster for kids that age!  It is a great story!  Here is a link to the first book:  Link

It looks like there are 12 volumes total.

-Shannon

If he likes video games, I recommend the Kingdom Hearts manga.  Definitely not as good as the game but it's a start! (I got my brother to read it! )

Naruto is long (47 volumes and still ongoing) but it has a likeable hero, and plenty of action; what boy doesn't like ninjas???  

Another long one, not quite as long, is Rurouni Kenshin, a samurai story, 28 volumes.

Maybe check out if he likes mecha stories, there are tons of them, since he likes space war stories.  Maybe the Gundam manga -- there are a gazillion of these and they are classics of the genre.

Dragonball and Dragonball Z are action-hero type stories he might like.