Well, I think command lines are an essential thing (or at least highly recommend imo) to know when using linux. Anyone who says you don't are ultimatly B.Sing themselves.

As for me, I find the command line a lot faster than interfaces for quite a few tasks. (I'm not going to deny that I aint a command line expert e.g my bash scripting are non-existant). I'd obviously use firefox over links but I find running sudo apt-get install build-essential for example to be a lot faster than finding synaptic and searching for build-essential.*

I mean try and make things easier for yourself but taking the time to learn command lines will easily save time later on doing tasks in linux.

As for compiling stuff; ./configure --prefix=/usr; make install

(ok, i exaggerate a bit but most of the source packages in archives actually do work like that from experience. for everything else, there's "cat INSTALL" :P)

*Ok, I lie, you can type apt://build-essential in the firefox address bar in ubuntu to install applications too.