Skypeout Newbie ok?

decies

Ok please bear with me with this ok complete novice,downloaded skype tonight ok.When i was doing this i clicked on this btstacker.exe (publisher broadcom Corperation)which apparently is my access control or whatever
I dont know should i clicked on this or what will i do.
Should i remove it or leave it there??????????

Also i had a few e-mails from nasa and the wwf from the usa in my inbox,so when i saw these icons i clicked on these and dialed through to usa.
It dialed through skypeout thanks.
Do i get billed for that ,how much ? And who bills me?
Am on eircom broadband thanks..
Sorry for stupid question,but am new to all this.
Thanks