2.3 to 3.0 upgrade suggested method

[carl b]

greetings,

i have 2.3 installed via cd and working well. now that i would like to 
make more use as a desktop machine am finding the packages a little out 
of date. apt-get is working well, pointed to ydl site directories for 2.3.

recommended upgrade path?
1. download iso's and install 3.0
2. install yum and direct to 3.0 directories / update / upgrade
3. if i point apt to directories for 3.0 will it upgrade the entire system?

have been monitoring the group for about a month and haven't seen this 
addressed yet. help
4400, 96mg ram , 4gig & 1gig mac os9.1 - dsl

carlb