2009 MacBook running OS X 10.7.5, 
2.26 GHz Intel Core 2 Duo, 
4 GB 1067 MHz DDR3. 
92.13 GB free out of 499.25 GB. 

Logging in takes a couple minutes, opening applications takes anywhere between 5-30 seconds. What can I do to speed it up just like when it was new?