When it comes to recording Skype calls, there are software options, such as Pamela, or Total Recorder, which run on the computer. I prefer using an external recorder though, because the PC already has enough to do, and recording is a demanding, real time process.
I have used the Zoom H4 for recording Skype calls with great success. The Zoom has two additional inputs that can be selected instead of the built-in mics. My method involves taking the output of the PC and feeding it into one of the inputs of the Zoom, and a standard mic with an XLR lead into the other. I use a Sure SM58 for this, although it could be any mic.
I still use a separate mic plugged straight into the computer so the other person can hear me - this can be a cheap mike if you wish, because it does not participate in the recording, but merely conveys your voice to the other party.
You’ll need the right lead to connect the computer audio output to the Zoom’s input. The computer has a 3.5mm jack socket, and the Zoom’s hybrid inputs will accept, as well as an XLR plug, a 1/4 inch jack. Suitable leads are available from music equipment stores such as GAK.
So to recap, the Zoom has a mic and a lead from the computer plugged into it, and the computer has another, cheaper mike plugged into it. Both mics are placed together, to pick up your voice.
One last thing to be aware of. The two inputs on the Zoom have gain controls to alter the input sensitivity. These are labeled L/M/H for low, medium and high. I find that the input from the computer needs to have it’s gain set to low (L) and the input from the mic needs to have it’s gain set to high (H).
The result is that you get a recording with you on one track and the other party on the other - making post production nice and easy.
Best of luck with your Skype recording!