RAM and hard drive question about core duo MacBook

Sorry if this has already been asked and answered here before but I can't seem to find it so I thought I'd give it a shot.

I have a first gen MacBook core duo with standard 512MB memory and while it's worked good for me, even having the whole Adobe suite runs fine (at least maybe because I haven't experienced using it with other specifications), I just feel like its time to upgrade.

What I'm wondering is if there are limitations on the amount of memory and size of hard drive since its a little older computer.

Thank you psychofreak, although that kind of makes me sad I was hoping to go all out on 4GB.

And thank you for the welcome canadasRAM and for the suggestion. I looked in this forum for to see if something had been already said about it but didn't even think of looking at the guide tab. I'm sure it will come in handy in the future