Parts of a song

Hi there...I am interested in song writing and improvisation. But my problem is that I can't take theory lessons maily due to lack of time, so, you may help me out with this subject. I want to know the frame of any song. I don't know: when one writes a song, how would he go through it? What are the possible progressions to make the song flow? Thanks...

It depends on what kind of song you're trying to write. If you're writing a punk song, then there's basically just verses and choruses. But if you're trying to write a complete song, do what I do and use what I like to call, "the everyday kickass Metallica song." This setup for a song is what most of Metallica's songs are in. This is how it goes: intro, verse, chorus, verse, interlude, verse, solo, chorus. If that seems to difficult and you're a beginning guitarist, just go with the extremely easy punk song stuff. And if you don't really care much for any of those, just listen to one of your favorite songs and look at how that is setup, and try to do something similar.

Thanks a lot :-) That's what I thought of in the beginning: to use my favourites as a template for my own songs. But how can I utilize chord progressions to make the song flowing? I mean: what makes every part of the song unique and seen as a unique unit? What are the characteristics of each part that make them unique so that I can know the verse in every song I hear? Sorry if it sounds stupid, but I would really appreciate your help :-) Thanks...

Umm, it's hard to nail down what it is about chord prgressions each tune, heaps of songs are written in a I, IV , V progression, that is the first chord of the scale, the fourth, the fifth.
For instance, in C, the progression goes, C, F, G.
These are played around with a bit, and if you make them all dominant 7th chords you get a blues tune. The reason I, IV, V is used so often is that together every note of the major scale is used in the three scales. This means that they hold all the notes the melody might contain. Obviously it can get more complicated than that, but that is a simple reason. The next most comon chord to add is the VI chord, or the natural minor. In C, this is Am. YOu get a lot of songs with combinations of I, IV, V, IV. An example is Eagle Eye Cherry's Save Tonight, which is VI, IV, I, V, or Am, Fmaj, Cmaj, Gmaj.
Choruses will use slightly different chords, I will use the example of U2's "One" (because I like it).
The verse is Am, Dmaj, Fmaj7, Gmaj.
The chorus is slightly altered, with C, Am, Fmaj7, C.
Notice how the two progressions really complement each other? THis is partly due to the verse starting on the natural minor VI of the key, and the chorus starting on the Tonic (I). Also notice, that the Dmaj is not in the key of C, it has an F# in it which C does not have. Usually in C, the correct chord is Dmin, but Dmaj just seems to work here. Sticking rigidly to the key is not always best then, but it pays to not ignore the key completely. Another famous song with all major chords is "Hey Joe" famously covered by the Jimi man. The chords are C, G, D, A, E, all major. This works in the context despite them all being major chords.
Hope you get some ideas from this, and it hasn't just stuffed you up!