Beginner advice on paints?

I was a "returnee" modeler  too.  You really should consider an airbrush, the initial cost of the brush and compressor  will be born out over several years of painting enjoyment (well except when the darn thing gives you fits-sigh). That said you can brush paint models with acrylic paints but that family of paints is  faster drying than enamels, so look for some "extender"  (drying inhibitor)[ art /craft supply stores] to help slow down the drying time. Also the thinners you use will have an effect on the coverage and flow of the paint.  So I would recommend using your paint brands own  thinner, to cut down the variables a bit.

Regardless,  just build models, get the paint on 'em, as you like and check out the "How to's"

 http://www.finescale.com/home/videos/how%20to.aspx to get a start.

Oh and welcome back to the most fun you can have and to the forum 

While I second the recommendation for airbrush use I understand your desire to slowly get back into things and not invest in that equipment just yet. If you are going to hand-brush on your paint I would recommend the use of Vallejo Model Color acrylics. Do not confuse this with the Vallejo Model Air as these are a bit thinner and will not brush as well. In addition, before you apply the Vallejo Model Color be sure to prime the model as this will help the paint adhere and cover more smoothly. There are plenty of primers available in spray cans …one that comes to mind is Tamiya…but there are many in this hobby who use automotive primers (in spray cans). Another plus of the Vallejo Model Color is that the color range is quite large. They also seem to be, in my opinion, pretty prevalent on the market. Several local hobby shops in my city carry their full line as well as many online retailers carrying these paints.

You are lucky- WW1 aircraft are the best subjects for hand brushing.  A couple of years ago one of my model clubs held a challenge for hand brushed models, and almost all the entries were WW1 subjects.  Flat colors brush much easier than glossy paints.    Keep the brush reasonably dry- don't put big gobs of paint on it.  And prime surfaces before painting.  Spray cans of primer work fine.