Binary signed numbers

[Draggonn]

Hello all!
I'm having a little problem with binary numbers. The teacher didn't quite explain them to us (saying we won't need them during the course I'm currently taking). But I know they are very important, especially for courses later on.
I pretty much understood all the basic binary arithmetics such as addition, substraction, etc..
I just have a problem when it comes to the 1's complement of signed binary numbers. For example, if I have +3 written over 4 bits 0011, what is the notation (or respresentation maybe? I don't take the course in english so I don't know the write term for it) of 1's complement? Our teacher told us that is the same as +3, so the 1's complement of +3 is also 0011 for example. And he told us that the 1's complement notation of -3 is the 1's complement of +3 thus is 1100.

If this is wrong, then can someone please explain to me how to obtain the 1's complement of a positive and negative number?
Thank you in advance for all those who answer ^__^

[Ganon11]

This site may be able to explain one's complement representation of numbers. I'm not too sure - I've learned Two's complement representation, which seems much, much easier.

[Draggonn]

Ok, I have read the site, and I have also asked some friends of mine that took the course before I did. I think I pretty much got them right. If we have a signed number, for example +3 over 5 bits 00011, the 1's complement of that number is 11100 which is also -3. If we need the representation of 1's complement for -3, 10011, we use the positive number 00011, and get it's 1's complement. Is that pretty much it?
Thanks again for your help :)