Welcome Katie! I too am planning on doing most of my own wedding. As far as invitations, I was going to print my own too until I found some on Ann's Bridal Bargains and they were actually cheaper to have them print the invites than it would have been for us to at home. I am still going to make my own RSVP post cards, but I will have my invites printed from Anns. I would check out www.annsbridalbargains.com becuase they have a lot of inexpensive wedding supplies. I also love the Oriental Trading Company
Party supplies, crafts, party decorations, toys: Oriental Trading. They have a wedding section and you can order a catalog from both places, just for references. If you have any Dollar Tree stores in your area they have a lot of nice stuff too. I am getting my bubbles for my ceremony, my favor bags, and all my vases for my centerpieces. (plus more I'm probably forgetting right now. If you don't have on in your area you can order some stuff from their website Bulk School Supplies, Restaurant Supplies, Cleaning Supplies, Gifts & Party Supplies - DollarTreeDirect.com but you have to order in bulk by the case if you order from their website. Hope that's a good start for ya.