I was merely suggesting it as another alternative as the OP did say s/he was a beginner in electronics.
Thus I felt the OP might be trying to do things later on that would need a microcontroller rather than a pot controlling a 555.
I mean a software solution to controlling an item is a lot more flexible than a 555 circuit. With no circuit change, just a change in the software you can have timed loops, delays, filter user inputs, debounce keys etc. Personally, this sort of flexibility without picking up a soldering iron or changing a breadboard circuit gave me a lot of fun when starting without a lot of effort, this got me hooked.
If the OP then wants other input or output, the fact tweaking can be done in software is also a boon.
And the PICAXE is specifically targeted at beginners and programming them is so easy (not like other uC). They have a bootloader and free software, you just buy a serial cable (or wire up your own three wires) and use their free software. The PICAXE even have internal clok sources so the component count to get started is minimal. Plus they have heaps of really good beginner's documentation free for download (they only charge for the ICs, nothing else). A breadboard, a PICAXE and a download cable and you have a microcontroller development environment atached to your PC :)
(BTW I don't use them anymore, I'm AVR all the way but I think they are great for beginners)
D> > If you are just beginning it might be easier to use a PICAXE.