Hi. Modeling is one of those hobbies that you basically learn as you go. And what works well for one person may or may not work so well for the next. That's why there are so many ways out there to do things.
As far as instructions go, it's basically best to follow them, unless you see that there is a better way to assemble or paint something that would work better for your particular application. Again, this basically goes along with experience gained as you get into the building of more and more kits. Experience is a great teacher that just keeps on teaching as we all go along.
I agree with the other poster that liquid glue is one of the better ways to glue things together as this cuts down on the possibility of getting those unsightly lumps around joints that the tube glue will give you if you happen to get too much of it on when gluing two pieces together.
Don't forget the super glue as well, along with its fixing agent to be used to fill in gaps and such. Great stuff. Plus also a must have for glueing resin and PE.
And most importantly don't be afraid to ask question, esp. on this paticular site, about most anything dealing with modeling. There are all kinds of real nice people out there world wide who frequent this site that will more than gladly help you with what they know about your particular question. And by choosing this site you have gone a long way in that department.
Research on your particular subject matter is also pretty much a must, esp. if you go into doing any modifying of your kit(s) as you go along. Luckily there seems to be no end to the amount of things out there on the Net to help you with, not mentioning the folks here as well.
Patience is the key to modeling. if you become frustrated or stuck on something just put it back for a while and think on things. Some of this stuff is definitely not to be rushed, as that's the time we tend to make mistakes.
German armor was basically painted panzer grey till early '43. except in N. Africa, where a mustard type of color came into use earlier. But until that time the Allies faced German tanks in this basic color.
Take care, good luck, and welcome back, sgirty