Here's the spec for your model, so its PC2100 DDR SDRAM
Apple iBook G4/1.2 14-Inch (Early 2004 - Op) Specs (iBook G4 - Early 2004 - M9419LL/A) @ EveryMac.com
I would install a 1 gig chip if I were you
Apple iBook G4 Memory Upgrades at OtherWorldComputing.com
And Microsoft used to make Office viewer apps years ago, but with so many free tools to edit Office docs around, the demand for simple viewers has evaporated