i cant find stuff?

hi i have had this mac for almost 3 years and never really took the time to find out how it works / where stuff is etc.. anyway i want to find all the photos i have saved typed .jpg into finder and it shows a few hundred but none of the ones i put on through i photo and also fails to find ones i have in other folders on the desktop.

Your user directory would be a good place to start. iPhoto stores everything in the Pictures folder, either in its own iPhoto folder or in a series of sub folders organized by date (i.e. 2009/02/24/*.jpg) if I remember correctly. When searching for files, you should specify the folder(s) to look in, and have it search your user directory.

hi thanks but i think something is wrong. finder will not find other stuff i just typed dreamweaver and it did not show up so i clicked on one of my web pages and it opened straight up. the mac is running a bit slow the spinning round think keeps popping up. never had a problem before?