You used to be able to Canada with just a birth certificate until around 2011 when the laws changed. However you need a passport to travel pretty much anywhere outside the US now and you can use your birth certificate and license or state i.d. to get a passport. You need a visa to travel to a few places and you need 4 duplicates of your visa if you travel to Africa.
Yes. Or a certified copy. After June 1, 2009, you'll need a passport.
Yes and yes, unless you are traveling by road; on such case, you only need a birth certificate or ID.
Children under 15 can travel to Canada, using a birth certificate, as long as they are NOT flying. If flying, they would need a Passport.
You need a passport to travel there from the US.
A passport (air travel) or ID/birth certificate (land travel) and some money to spend are all you need.
No you need a passport as well.
Best bet is to have their birth certificate.
No, for international travels, you really need your passport. However, if you plan to land or sea travel to Mexico or Canada and you have your License and your Green Card and Birth Certificate, then you can but you still need the passport when you get back to the US for easier travel.
After June 1, 2009, you will need a passport. Until then, your drivers license and original birth certificate or certified copy will suffice.
If you travel by air, yes they do. Otherwise, they only need a birth certificate or another proof of citizenship.
Your friend cannot travel across international borders if she does not have adequate documentation. First of all, a birth certificate will not help you get across an international border. If she does not have a passport, US passport card, "enhanced" drivers license or "enhanced" non-driver ID, then she will not be permitted to enter Canada.