This is exactly what I do...
Inflatables, interactive equipment, dunk tanks, concessions, carnival games, party activities (spin art, sand art, candy art, jewelry art) entertainment, clown, DJs, karaoke, costumed characters, caricature artists, balloon twisters, face painters...party room...etc...etc...etc...
Insurance is a b*t*h...and the labor is intensive...it looks easy to just pop 'em out of a van...wheel them to a backyard...set 'em up and go...but the first day you have to roll up wet one (from rain)...call me and let me know how much you'll sell me the used one for...lol (you'll have to call right away cause if they sit too long, you'll have mold and mildew issues...) storage is a beast because they take up alot of space...you do need a place to air them out (while inflated) if it does rain...and a place to clean them (rain or not)...
As far as carnival games go...they just always seem to look better when they're not homemade...and your customers will want the look...There are various places for games...
gold medal tub games are pretty good...as are
www.hufferamusements.com They also have some pretty amazing table games...
There are others...if you just do a general search for carnival games on the net
I've been at it for some years now...so I've got the staff to help me out...but ask away if you have any questions...and feel free to check out my site...it'll show you the stuff I've got...
www.ChicagoPartyPlace.com