Safari :: Can't Add Any Bookmarks Anymore Using The Plus Sign Next To URL

all of a sudden i can't add any bookmarks anymore using the plus sign next to URL.  searched many websites which offer adequate solutions to fix but i cannot follow as folders/files can't seem to be found.  I even had trouble finding the safari folder as it don't exist under library-  may be clueless but i seem to have 2 folders for library: one under macintosh hd, the other under the system folder.  also can't find the bookmarks.plist file either using spotlight. some sites say locate the com.apple.safari file, which seems to be missing in either cache folders, example of what is there is com.apple.components2.localcache.audiocomponents etc.... its frustrating especially when you find a good website to add to an already organised bookmarks folder. 

NOTE- i did find safari folder via spotlight but within it was 2 folders of bookmarks and history and both don't have the bookmarks.plist file and only endless "webbookmarks..." 

Info:
iMac (27-inch Late 2009), iOS 5.0.1