So I'm pretty much newb in training and my buddy came up with a weird plan.

Lets say we do pecs, here is an example of what the plan would say:

8 reps on bench
10 secs rest
12 with dumbells
10 secs rest
20 butterfly
90 sec rest

So I'm not sure what is the purpose of such a training and if it's effective. What do you guys think about this formula (8-12-20)
I didnt find much infos on google

sounds like circuit training but i wouldnt just do some made up program
first figure out exactly what you want to gainz from your lifting
second do a little reading and pick a tried and true proven program that can accomplish your goalz
maybe
i googled a couple places
http://stronglifts.com/5x5/
http://www.bodybuilding.com/fun/luis13.htm
http://www.aworkoutroutine.com/workout-schedules/

Well... first off, what are you intentions with this routine? Are you trying to build muscle? Lose Fat? Better cardio, etc?

This just seems like your normal supersetted bodybuilding routine. However, it is being done with poorly chosen exercises (imo).

Generally, supersets are done when people either need to get done quickly or they're trying to be in better cardio vascular shape.

In bodybuilding, they're useful but I feel as if they're over used. People like to pretend that being more tired = more gainz. However, that is not true. You need adequate rest times in order to maximize the load you're able to put on your muscles.

Personally, I think you should ditch this routine and start doing a starting strength program if you're actually trying to make gainz. How can you expect to maximize the weight when you're doing bench followed by dumbbell bench? You just aren't going to.

Generally, I only recommend supersets if you're A. Burning out a muscle at the end of a hypertrophy day B. Want to hit two muscle groups in an efficient manner (aka back and chest).

I love this:
http://stronglifts.com/5x5/
Do u have access to all the equipment you need, such as a gym, or is it just basic Dumbbells you have at home?

doing giant sets for absolutely no reason, a beginner should stick to a simple routine, you should only go into the fancy stuff if you find yourself not progressing anymore

doing these without experience doesnt really add any benefit, and you'll be misereable, fatigued and your form will probably be crap