Physical printing has been the largest question for new players.
It's always a little tricky converting digital images into real life.
In the picture I show eight steps.
1) Select your images or files.
2) Saving the file. Whether jpg or zip or rar, choose the right folder and save it there.
3) Open your files and view them with whatever program you are running for your main image viewer. Here I will have to to view whatever version you are running. I use irfanview or gimp (cause they're free).
4) You should be familiar with the settings of your printer. Choose the borders of a 3x5 index card to .25 on left, right and top and .5 on bottom. This should work with most printers.
5) Get your index cards online or at the store, but jog them (loosen them up and then make sure they are nice and even with eachother).
6) Load up the cards. Move your printer guides to match the cards. Don't shove them in, read your manual for instructions.
7) Hit that magical print button. You may want to give a couple of test runs in case of wonky borders and margins. Don't get mad and do a "PC Load Letter Beat-down". Just be patient. If the borders are still not working on the top, you may want to flip the image horizontally to print them upside down. I do this on my resource cards so I can have my Resource Icons closest to the bottom.
8) Collect 'em
A Note on Deck Building with commonality: Make sure to remember that Common Cards (Unmarked) are only allowed 5 per deck of each name. Uncommon is 3, Rare is 1 and Ultra Rare is 1 per game.
Purchasing colored Cards for ease of use: Sometimes stores offer green index cards or pink. BUY THEM if you can afford it. A colored index card deck is easier to sort out in the end with who's color is who's.