.NET cracking tut or hints ?

OK, different question :

I've got the code dissassembled into IL, I found my piece I was looking for, but now what ?
Is there a way to debug it, or what other tools are needed ?

If I have IL like this :

IL_001f: call string [Idxx]xxx.Lib.Misc.Idxx::GetSerial(string)
IL_0024: callvirt instance string [mscorlib]System.String::ToUpper()
IL_0029: stloc.2
IL_002a: ldarg.0
IL_002b: ldstr "edSer"
IL_0030: call instance string [CtlLib]xxx.Lib.CtlLib.SomeControl::GetInput_Value(string)
IL_0035: stloc.3
IL_0036: ldloc.2
IL_0037: ldloc.3
IL_0038: callvirt instance bool [mscorlib]System.String::Equals(string)
IL_003d: ret

how can I "sniff" what values are compared ? How can I found, where exactly are those instructions ? Is there a breakpoint (symbols ?) to set in SIce , or it can be debugged in some other tool ?

And another question : can I "rip" some function (I mean REAL asm code, not some pseudocode) from .net dll ? Or call that function from dll from my non-.NET app ?

Thank you very much
bye