That's probably the easiest way. As mentioned though, you need to line mesh. Put keypoints [K,num,x,y,z] at all the intersections. Then draw lines from keypoint to keypoint [L,kp1,kp2]. Then, you define your sectypes as I mentioned above.
At this point, I'll give the obligatory RTFM for defining beam sections.
At that point, simply LMESH the lines, apply boundary conditions and solve. From the sound of it, you need to spend a few days and just go through the help, do some test cases, get accustomed to the software.