Hi Mary. I'm new to GCU, too, and before I started making cards, I never had any digital/computer art experience or skills. My daughter insisted I get onto Picasa and Picnik. That's a great starting point.  
I cannot afford any actual art programs at this time and have few tools available, but by being a bit creative I can make lots of fun frames and borders, using Picnik. It's free and easy to use.
They have several types of frames you can use: "drop" frames with neat shadows, museum matts, and plain borders which you can select any color under the sun. For wider borders I just repeat the same border two or three times. There are special effects, vignettes,  and some clip art that is free, too. Just get into Picnik and start playing around. Experiment and make sure to click on "save a new copy" when the notice comes on the screen so you won't lose your original.
 I use borders and frames a lot in order to make a photo fit into the 5X7 format without having to crop the living daylights out of it.
Take this from someone who still feels "computer illiterate": Picasa and Picnik is not hard to learn and you will have a whole new toolbox to inspire you.
Happy creating!
Ramelle "Eloquence"

do be sure to check that any of the frames you use are permitted for commercial use when they come from sites like picasa and picnik and the like.  i have never checked on them.

Just wanted to reinforce Denise's comment about checking that graphics, clip art (frames) are permitted for commercial use.  Some years ago when I first started on Etsy, I was using graphics from a personal card application only to discover that no graphics from the application, including frames, could be used for commercial purposes.  Had to pull a year's worth of listings.  From my experience it is always best to check their terms of use up front.  "Stock files" which include clip art, samples, fonts and other graphics in some applications are restricted from commercial use. I discovered later that even Photoshop has some of these restrictions.

If you are using Photoshop, you can get hundreds of nice STYLE Presets that can help you make frames for your work.
 
 

First of all - your cards are amazing and strong enough just as they are!  But as a fellow artist, I understand if you are wanting to see if something else might take you to another level or open up another style for presenting your art.
 
Do a web search for photoshop frames or for clipping masks.  Do some playing and exploring and READ ALL LICENSING details before you use anything.  The places that give you commercial access (or charge just a stipend), bookmark and visit often.  When you can, donate to those artists to keep them offering their work.
 
And as you get more comfortable with frames and clipping masks - do some searches for tutorials on creating your OWN from scratch.  You'll be surprised how easy it is!
 
Anyway - that's the progression that got me to making my own now.  A year ago you likely would have seen my head spin in confusion over how to do this now it is second nature