Actually, it's the most important thing to remember, and yet, so easy to forget. So good call... I learned this the hard way when I started creating custom roms.
Good luck @LaTormenta! There are lot of good resources/instructional posts within this site as well as folks who are happy to address questions.
I'll add another helpful tip... if you do run into an error or whatnot (so, you "hit a wall" as it were), when asking your question to the community, give as much detail as to what you were doing when it happened and perhaps, include screenshots. Having seen this play out here, over and over, as well as the fact that I work for a software development company, I can tell you that it's a challenge to help troubleshoot without details.
Again, good luck! Looking forward to the end result!