Well after three weeks of buying almost every color paint and getting tools from pin vise to airbrush/compressor; I finally glued my first a parts together!! I am building the Tamiya Horch. Some questions have arisen:

1. Do you wash the model again in detergent before painting?
2. When painting the undercarriage of a vehicle do you paint separately or together and mask. Ex bottom (transmission axle etc) I'm going to paint black/burnt umber top panzer grey. Should I paint the bottom before I glue the two halves?
3. When drilling using a pin vice how do you hold such delicate things as gun barrels so as not to break them and impale yourself. BTW I tried, with success, drilling out the muffler!! But that was thicker and sturdier than mg barrels.

I am using all the advice I can get from this web page sometimes overwhelming so my first attempt will be simple.

As far as drilling, I first use a sharp x-acto to start the hole, then work from there.
You sound somewhat like myself, I havent seriously done anything in 15 years.
I went through the same thing, but I didn't splurge on the airbrush/compressor yet. The wife is ready to kill me now that I've got another hobby.
John

Congrats on rejoining the model-building club! :-)

1. Do you wash the model again in detergent before painting?
It's always a good idea to wash it a bit before painting. Very gently in a sink of warm soapy (dish detergent). Rince it real good and be sure to let it dry fully. I sometimes use a hairdryer on low setting.

2. When painting the undercarriage of a vehicle do you paint separately or together and mask. Ex bottom (transmission axle etc) I'm going to paint black/burnt umber top panzer grey. Should I paint the bottom before I glue the two halves?
I paint it all one color first (priming it is a good idea in my book, it helps show any defects.) A light grey color is good for this. If there are any things you missed you can go back and fix them before you get to far into finnishing the kit. Than paint the vehicle the overall color all over. Than you can pick out the individual colors for each detail.

3. When drilling using a pin vice how do you hold such delicate things as gun barrels so as not to break them and impale yourself. BTW I tried, with success, drilling out the muffler!! But that was thicker and sturdier than mg barrels.
Just like Dubanka said - use the tip of an x-acto knife to get the hole started. Just be sure to align the drill bit with the part to be drilled accuratly...you don't want the bit to end up going out the side of a barrel.
None of these tips are set in stone, there are several methods which people use for the above.

I used to drill gun barrels using the drill between my fingers. If the drill is in good sharp shape this method is relatively easy.

Toni