ok, so the basic objetive

we have the initial registers context

[ o d I t s Z a P c ]
[                   ]
EIP 56556180 | .aUV | => `main in section .text of /home/sdancer/projects/ms2/res`
EAX F7F88D88 | .... | => 0xFFFFDAEC => 0xFFFFDC6E => "_=/bin/gdb"
EBX 00000000 | .... |
EBP 00000000 | .... |
ESP FFFFDA4C | L... | => 0xF7DC8B41 => `__libc_start_main + 241 in section .text of /usr/lib>
EDI F7F86E24 | $n.. | => `_GLOBAL_OFFSET_TABLE_ in section .got of /usr/lib32/libc.so.6`
ESI F7F86E24 | $n.. | => `_GLOBAL_OFFSET_TABLE_ in section .got of /usr/lib32/libc.so.6`
EDX FFFFDA74 | t... |
ECX BC7C3964 | d9|. |

and we follow each instruction, as the instructions tranform the registers, we transform them too with the same effects
then there is the stack, push, pop and mov will transform the stack
and also the stack pointer (ESP FFFFDA4C), the stack pointer indicates where in the stack are we now
0xFFFFDA4C: 41 8B DC F7
a push will decrease the pointer by 4, a pop will increase it by 4
so lets execute the next instruction pending
so the stack moved to 0xFFFFDA48: 00 00 00 00
the contents of the register where pushed into the stack position
    0xFFFFDA44: 24 6E F8 F7
another push
 0x56556181 <l0x1dbf71b>:	push   %edx
and the stack will move another 4 bytes down(visualized up)
this instruction will push edx, so the contents of edx = FFFFDA74
will be placed into 0xFFFFDA48: 00 00 00 00 
                    0xFFFFDA44: 74 DA FF FF 
ok, so now the new pointer is FFFFDA44
so we can translate the push(parameter) operation as
 esp = esp - 4
 [esp] = parameter

that is it, we transform the registers and the stack as the real cpu would following the execution
there is another class of instructions that we need to take care of, control flow
which change the excution pointer (jump, jxx, call, ret, etc), to understand these is left as another exercise with the debugger
just step over them (?)
pop edx instruction executed will load the contents of current esp on edx and increase the esp by 4
ok, have fun