Hello Tom,
I will give you my two-three months feedback..."I too came back" after about 30 years. I will try and hit all the questions I had once I found this site....in other words what has changed in 30 years?
1) GLUE....super glue is great, use it wisely....the other glue I use is Tamiya brush in a bottle glue..and there is a clear glue made by testors...for clear stuff. Anyway, the super glue and all of the derivatives are really well done and make assembly easier and you can glue and move on with the subassembly.
2) PAINT I tried Vallejo and Tamiya....for whatever reason, the Tamiya seemed better for me. There are a ton of weathering dusts and paints and oils and techniques that are really enjoyable to experiment with....way more than 30 years ago The TAmiya has lots of colors and works well with brush and air brush
3) AIRBRUSH I bought a Grex and I am happy with it, there are lots of options....and you can do without for the first few builds...to me is is not so much that one needs practice with the airbrush, as much as one needs to make all the stupid mistakes of a beginner before one become handy with the darn thing. But, as you get handy, you can not live without it....A Grex with the small compressor is very good...some $$ here
4) TOOLS...lots more cool stuff available..this is the fun part
5) WHERE TO BUY....I like the Eduard site, Sprue Brothers, and Squadron and Scalehobbist...there are many and the forums will lead you to many...I liver in Vermont, so shipping stuff in is about all I can do....The Sprue Brothers stuff arrives fast
6) WHAT TO BUILD...I like WWI planes so that is what I build, I started with 1/48 scale as that seemed about right and I think it is (in terms of my eyes and display space)....most parts I can see......if you drop in on the floor, the model did not need the part anyway.....I am going to build a few 1/48 and then look into the larger more $$ 1/32 planes anyway, if you look hard enough, you will find images of what you want to build
7) RESEARCH I like to look at the techniques that others use, for specific items, I do not yet get into that detail...but I love to look at how foiks build a cockpit....then we close the darn thing up and you can not see it ! But I also do not want to know everything, I want to experiment on my own too. Great magazine are avail.....I like this one, FSM and from militaryillustratedmodeller.com these guys have vehicle and airplane version of the magazine..and Both FSM and this one have great images and building techniques....note the Klear floor was treatment of cockpit canopies--makes you wonder who thought that one up? And all kinds of very cool applications..I know there are ton more magazine....and have the fun is looking at the ads in the magazines.
8) MODEL-WHATS NEW This is fantastic...there are resin parts and photo-etch (PE) parts and all kinds of stuff you can get to make a give kit more fun and way better looking a gazillion more detail parts... look in the ship forum here for what a guy did with the Cutty Sark, tremendous. ..that is one of the reasons I started with Eduard, you can buy the kit with all the add ons...PE stuff is tricky and get a bender if you get into these things.....some PE I just leave on the tree for I could not see it once I cut it off anyway.....
Do not for get your wallet and have a blast.
Good Luck