Q: slow start up

How long exactly is "ages"?

What is on the screen for the longest time?

Direct you to the proper forum for MacBook :

This forum deals with a desktop/tower 65lb Mac Pro

http://www.apple.com/support/macpro

You should consider your backups, use ML Recovery Mode to repair the disk at minimum, then return with a Safe Boot.

Recovery Mode

http://support.apple.com/kb/HT4718

General purpose Mac troubleshooting guide:

Isolating issues in Mac OS X

Creating a temporary user to isolate user-specific problems:

Isolating an issue by using another user account

Identifying resource hogs and other tips:

Using Activity Monitor to read System Memory and determine how much RAM is being used

Starting the computer in "safe mode":

Mac OS X: What is Safe Boot, Safe Mode?

To identify potential hardware problems:

Apple Hardware Test

General Mac maintenance:

Tips to keep your Mac in top form