where to start with aircraft models?

I would like to offer a tip....
DRYFIT DRYFIT DRYFIT!
Dryfit before you paint the part....dryfit after you paint the part. If youve set the model aside for some time....dryfit before gluing it just to be sure it fits....and that you modified it as necessary before it got set aside.
I also try to do several things at once....if Im waiting for paint to dry on a part I'll paint other parts....Everyone has different approaches. I used to be bad about not dryfitting and got so frustrated when something either didnt fit or didnt look right until it was slathered in glue! Now I dryfit and Ive incurred less problems...oh sure the occasional piece slips my memory and gets through without dryfitting.....

I'm not a great weathering modeler but some ideas are of course rust, places where paint has been nicked off, a black streak from the engine exhaust, mud on the wheels, if it's a starship you can check out places for battle damage techniques.

I think one of the main things a modeler needs is patience. Waiting for the paint to dry before touching, waiting for the glue to dry before putting the assembly on the model, ect. Sometimes I get excited and do things before their ready to be done and screw something up, and then thats when I stall. Usualy fallowing directions is the best way to go when your not sure, but one of my best tricks when a project is looking long and difficult with lotsa pieces, i put all the halves together. Put the haves of drop tanks, missles, pods, wheels, engines, tail planes, wings, ect. Anyhting that doesn't need more pices put inside. You can usualy take care of a third of a models pieces like this in a couple hours. Then the project doesn't looks so difficult and Im less likely to burn out. It's all about finding what works for you. As for weathering, thats also a preference. Some use washes, other pastels, mixes, and other things. I use all types of things. One technique to master is dry brushing, cuz you can add details to the cockpit, or put scratches in floors, or anything else you can think of. Also, remember when your weathering what type of environment your model would be in in real life. If your operating in a desert, you'll have more paint faded on top surfaces and less fade underneath, and in wet climates, you may have more mud on the tires. The best thing to remember is don't over do it, the most subtle effect can really make your model come alive. To much looks akward.

I use a liquid cement called dichloromethane.
MEK also works.
I run the brush down the seam 1 inch at a time and make sure that both halves are perfect before proceding to the next bit.
The extra few minutes spent joining fuselage halves/wings etc means that I rarely have to sand too much and never have to use filler, thus making the build quicker and hassle free.
The main thing that stops me from finishing my kits is that I really only feel like using the airbrush at night and the compressor is too loud

I tend to do the cockpits first with all the detailing. When I stall, it is usually over a fit, fuselage halves for instance. I tend to simply pack it up and put the box on the shelf. There are two piles, one I know I will never complete. The other is in a state of hibernation and I know if I get to it fresh, I can usually figure it out. I feel I am going great when I get the cockpit done, fuselage halves together with the wings and the tail, then I prime it silver. At that point, I know it is done. For me the most satisfying part is the painting. If I get primer on, it is going to get done!

If you would like to learn more about weathering, I would suggest doing a search in the "Techniques" section. There's a lot of good information there, and you may find the answers that you seek. If you have specific questions, try to narrow your question from the general "weathering." That's kinda like doing an internet search for all titles containing the word "the."
Hope this helps.

If you think you're going to stall, put your nose down.

What about weathering? i have trouble on that

To finish any model it's improtant to look at the kit and see which things can be done in what order. There is always a sub assembly that can be completed while the paint is drying. But if all else fails, just set the kit aside and take a break before you get burned out on it. Do a little research, watch a show, or surf the neet for ideas that'll re-energise your reason for building the kit in the first place.
A lot of modelers have several projects going on at the same time and go from one to the next when interest tapers off on a project. So do what works best for you.

I'll get off the soap box now.