You can download an owner's manual from the Ariens website for free. Go to Ariens dot com, click on customer service, then click on "download manuals" (or something like that), enter your model and serial numbers and voila!.
According to the ariens site, repair and service manuals are not available.
If you need a Tecumseh engine manual, search for the manual. Someone has posted the link to the entire Tec manual somewhere. It might even be on this site, I can't remember. It's a big pdf download (maybe 30MB), but it's over 100 pages, and it's free.
As for a general repair manual, I think that there might be a few out there like Chiltons or Haynes that offer a book like "General Snowblower Repair" or something like that.
Best of luck,
Ralph