hmm.... a few gmax questions:
1) what do you name things? i know the landing gear, but what do you name the second and third sets?
2) how do you zoom in and out?
3) how do you re-orient the perspetive view without rotating it

Well, as for the naming: there is a plugin you can download that has all the names that gmax recognizes for FS and will automatically insert the names when you press the corresponding button.  Problem is, I'm not at my computer and I have no clue what the name of the tool is.

Joining things together.  Select one of the objects you want to join together and find the button labled "Attach" under the modifier stack window.  Press this button and then go find the other object you want to join together and select it.

You will notice that the object now has a seam in the solid view where the two were joined.  To solve this, go into subobject edit and select "Vertices".  Highlight all the vertices surrounding the place where you just joined the two objects.  Scroll down under the modifier stack window and find a section labled "Weld".  The button directly below the word Weld is what you are about to use.

Next to the button is a little window with numbers in it.  This is the distance that will be allowed between two vertices before they are welded together to make one vertex.  I use something like 0.125" or 0.0625".

Now press the button labled "Selected".  If this worked right, the seam should have disappeared.

Sorry for the confusion.  The attach button isn't in the modifiers stack.  Its in the scrollable section just below the modifers, where you can hide things and unhide them, as well as many other functions.