[iMac] Question about iPhoto

[Pat]

I have a G5 with 512 ram and yesterday, while trying to add photos into 
an album, things froze up when I decided to play a slideshow.  Now, I 
had a couple of other programs open, so after a restart, with nothing 
opened, I tried again.  These are 5 meg pictures, but is that why it 
froze again?  Do I need more ram?  If so, how hard is it to add for a 
homebound type with no dealer in the area?

Pat