hi all im a new arduino user, have had one laying about for a while and have done a couple basic led exercises, and now i want to hack one of my kids toys to be a very simple usb controller which i want to send keystrokes to traktor(dj software). i know its possible to end up converting to midi messages thru a 3rd party software, but since im new, and since this is going to be a toy , i dont mind dealing with the limitations of using only keystrokes.
i initially started this project as a keyboard hack, but being the noob i am im having a hard time soldering to the keyboard pcb 
so i figured id give it a try with my uno.
from my tinkering with the usb keyboard brain i tested the buttons and switches on the toy im planning on using and it all worked wonderfully until i tried to attach the jumpers and strip board to the keyboard PCB. basically the solder wouldnt stick to the pcb very well and i was frying stuff trying to do work thats probably still a little over my head.
so my question is, can someone recommend a good place to start wiring these buttons from the toy to my arduino, and learning the code i will need to make it all work?