you will also need to know that you need designs in .sew format, unless you want to spend MORE money for software to convert other formats to yours. ( BuzzTools/BuzzXplore, Embird are just two you can download them from online at their sites..www.buzztools.com and
http://www.embird.com)
Your machine was made by Janome for Sears...I think it's the Janome 9500 it's comperable to. (also .sew format) you can ONLY embroider designs that will fit in your biggest hoop.
Be careful where you buy designs. (don't buy from Russia or the middle east...they tend to have viruses in their sites...they also digitize American cartoons and things that are trademarked and copyrighted...thats a NO, NO...)
http://www.secretsof.comhttp://www.windstarembroidery.comhttp://www.designzmall.comhttp://www.oregonpatchworks.comhttp://www.stitcherymall.comall these sites have thousands of designs and are reputable people.
you will need GOOD embroidery thread. (stay away from Coats/Clarks...it will fuzz up your machine and cause problems.) use good bobbin thread too..use a new needle for every 4 designs. ( otherwise you will have problems with nesting and tearing.) make sure you use proper stabilizers for all your fabric. You can use Janome feet/bobbins/needles, that will fit the 9500 machine.
http://www.janome.com click on USA.