First we need to know which one of the 9 different models of MacBook you have. To see which model you have go to the Apple in the upper left corner and select About This Mac, then click on More Info (and then System Report if you’re running 10.7 Lion). When System Profiler comes up check the Model Identifier and post it back here.
The Early 2006 model 1,1 Core Duo can only run a maximum of 10.6 Snow Leopard.
The models Late 2006 Core 2 Duos 2,1 through Early 2008 4,1 can only run a maximum of 10.7 Lion.
The Late 2008 model 5,1 Aluminum Unibody through the Mid 2010 White Unibody model 7,1 can run 10.8 Mountain Lion and 10.9 Mavericks.
You have to understand the difference between an Update and an Upgrade.
An Update is a free change to add to the base code or as a bug fix within an existing Operating System. Such as the .8 added to 10.5.
An Upgrade is a complete new Operating System that must be purchased. Such as 10.5 Leopard to 10.6 Snow Leopard.
10.5 Leopard was written for Power PC Macs with code added to force it to run on Intel processors.
10.6 Snow Leopard has completely rewritten code and only runs on Intel Macs.
10.7 Lion used some 32 bit which allows it to run on Late 2006 through Early 2008 MacBooks and a lot of 64 bit code.
10.8 Mountain Lion is pure 64 bit, which excludes more systems than Lion did. It can only run on the Late 2008 through Mid 2010 MacBooks. It's not something you can add memory to, for example, as it involves the base architecture.
The App Store version of iLife ‘11 programs (iPhoto, iMovie, iDVD, Garage Band & iWeb) will only work with 10.7 or 10.8. You can get the iLife ’11 DVD which will run on 10.6 on eBay or Amazon.com fairly cheap.
http://www.ebay.com/sch/i.html?_odkw=apple+ilife+11&LH_Auction=1&LH_BIN=1&_sop=1 2&_osacat=0&_from=R40&_trkparms=72%253A1234%257C66%253A2%257C65%253A12%257C39%25 3A1&LH_PrefLoc=1&_sc=1&_trksid=p2045573.m570.l2632.R2&_nkw=apple+ilife+11&_sacat =18793
http://www.amazon.com/Apple-MC623Z-A-iLife-VERSION/dp/B003XKRZES/ref=sr_1_1?s=so ftware&ie=UTF8&qid=1376932206&sr=1-1&keywords=ilife+%2711