Links are a tricky beast for those that have never tried them before. I might have misunderstood your but from what i read you might be a lil confused on what a link is
The first video in TBirds series (Stickied in this sub forum) explains combos very clearly and thoroughly. Even if you think you know combos back and foreward you may wanna give 9 min. of your time to see it, you will probably pick something up you didnt know. [media=youtube]Qa4GJQFYM1s[/media]
heres the thread with all the videos, i highly recomend them. Not only are they informative and well made, but tbirds accent is fukin rad (just me?)
&& about plinking, what it does is trick the game into thinking that you input a command twice, one frame next to the other, instead of once. the way this works is by pressing the button you want to double up on and then pressing a button of inferior priority.
The first example that comes to my head is balrogs crouching jab jab strong. so the way it will look on the input data screen of the training room is you will see the crouching jab, then another, then if you are plinking correctly, you should see the crouching strong immediately followed by crouching jab and strong at the same time. this puts two crouching strong inputs right next to each other (1 frame and the following frame).
If you know how to double tap your right hand motion will be similar except instead of hitting the same button twice, you will first hit the button you want followed by the second button, ussually the one next to it on the left.