here is lots of good advice here which I am going to try out, and ive used tff on a 600mhz g3 (brutal slow) and asked the question to see how much worse it is as most people have 333mhz to 500mhz g3s and 600mhz up g3s were generally the "high end" models and people opted for the 400,500mhz cheaper imacs. my point is, I have experienced tff on a high end g3 and its not usable.
Generally, to get by online with a PPC you have to work with a few browsers to achieve certain tasks - they all have their merits.
If you state what Mac you're using and what you need to do with it you'll have a better chance of having a constructive dialogue in here.