For startups, you can start (pun intended) with Windows Startup Programs Database, BC - http://www.bleepingcomputer.com/forums/f/85/windows-startup-programs-database/
Between that and Google, it's easy to find out what any item might be.
And...you can use this tool to disable, delete, enable startups: AutoRuns for Windows - http://technet.microsoft.com/en-us/sysinte...s/bb963902.aspx
If you use Autoruns...please only look at the items reflected on the Logon tab of the program. The various other tabs list items that are "startups" in the very broad context of the expression, but a user generally does not need to concern himself with those items unless troubleshooting other issues on the system.
If you are unsure of an item, just disable it (remove the check mark) rather than delete it. Removing any item does not remove that program, but it does prevent that program running unnecessarily at boot.