Stay close to him and keep the pressure on so they have to play your game instead of you playing theirs. Practice movement in general even tho I know its hard because Kirby is so slow and relies on telegraphed burst movement for more than half of everything if they play the matchup correctly, but good movement just really helps with everything. I spent the longest time in Melee and PM about this time last year just learning and grinding every movement trick out there.
SilentDoom made a post recently that I really liked in a thread called something like "How do I approach with Roy". To which he replied basically that usually when people ask that, they imply "What attack should I be approaching with" and then said you should focus more on movement, pressure, etc. in neutral instead of throwing out attacks. This was smash 4 Roy so approaching's a bit different, but I still liked the post so I thought I'd mention it.
Im sure these players wont mind, but here is one of my favorite videos of a Marth vs Link playing the matchup very correct. Look how Marth keeps the pressure on him so he wont get his stuff started. That same idea applies to Kirby as well.
https://www.youtube.com/watch?v=LQ0VyO4Ny-c&index=9
As for good examples of movement, there is a bunch out there. There are so many different playstyles I cant say to just watch just one guy. Everyone has their own style and they should just hone that specific style instead of trying to copy someone else's. I personally like Plup's Melee sheik style of movement, its actually similar how Ive been moving for a while, but its nice seeing that movement on a character like Sheik who kinda translates well to Kirby imo, instead of how I use to say I had a Axe/Jeapie (Pika/Falcon) style of movement which didnt really translate well.