Great stuff, getting nearer!
Taking the last category first, this is what you're aiming for. This is what WOL is designed to do - wake up an asleep PC over the net. For this to work you need to have a few things in place:
Your PC hardwired to a LAN via Ethernet (wake on wifi isn't common)
A network chip/card that is WOL capable
A WOL capable motherboard
WOL enabled in BIOS (you may be able to set this in the windows network settings too)
Access to port 9 on the PC (ie no firewalls that close port 9)
A program to broadcast a 'magic packet' over your network (gizmo does this)
So if you have all the above lined up in the right direction and a fair wind behind, then you stand a chance to make it work! This is why most of the WOL guides are in 'geek speak' because it isn't really for the feint hearted to be hassling about in BIOS and windows network settings! The BIOS settings are probably the trickiest since it may be called different things like PME and there may be various options. Enabling it allows some power to the network card even with the PC off, so that it can listen.
Note that the above is for doing it internally within your own network. So you should aim to have it working flawlessly internally first, before trying the port forwarding stuff on your router. In order to make it work internally, you shouldn't need the port forwarding stuff whose purpose is only to act as a bit of a traffic cop to wave the traffic (in this case the magic packet) from outside of your LAN to inside your LAN to your specific PC.
It doesn't sound like you have everything lined up yet if it doesn't work from inside your own home network, so one of the above requirements isn't quite met yet. Try and sort it from inside first before trying from externally.
SBR
PS: I've never tried it, so don't take my word as gospel!
