need a little help with an update and a few issues please!

hey guys. i have a macbook pro 15" that has os 10.4.11 and i am having issues. for one i cant log into yahoo mail, facebook or anything that requires me to type a captcha verification image, because where the image should be instead there is a little blue square with a question mark. this is also on alot of images that dont show up on my mac. i researched on the subject and someone said to use chrome or firefox, then i found out i need at least 10.5. also alot of programs i try and download require 10.5 or later. so i am kind of confused which os i should go with i dont need the best i just want to be able to use programs which currently dont work with 10.4. this is my first mac so i have never done an update before, do i just buy it through the apple store and download? and should i just try and get 10.5 or something beter i have no idea.

also this is not as important but i would also like to get resolved. my mac constantly gets popups eventhough my pop up blocker is enabled almost every web page i go to opens the page and then goes a few pages forward usually to some ad site on its own and i have to hit the back button a few times to get back to the page i originally opened.

any help would be greatly apreciated as this is my first macbook and i was super excited to get it thinking mac was way beter and i think it is but my mac is frustrating me between the pop ups and not even being able to check e mail or facebook or about 80% of things that computers are soposed to do.

thanks guys i know im a mac newb

Whenever you purchase a computer that's been used it's a good idea to reinstall the operating system fresh. I'm assuming here that you do not have the Tiger disks (OS X 10.4.X) to do a reinstall? If not, it might be best to purchase a copy of Snow Leopard (OS X 10.6.X). Leopard (OS X 10.5.X) can be used but it will be expensive and difficult to find a retail copy. You need to use a retail copy (black) of whichever version of OS X you wish to install.

yes i bought the computer used so i do not have the discs. so i need to purchase 10.6 snow leopard? from the apple store? when i install the discs will my music files be safe or will i need to buy and external hd to put them on first?

thanks

I doubt you'll find Snow Leopard retail discs (white)* at a retail store of any kind. You should try eBay or Amazon, etc.

*Tiger and Leopard discs are black.