Swapping Motherboards and different CPU

[Chris A Czerwinski]

Fellow Red Hatters,

Time for me to bite the bullet and to upgrade my hardware.
The PLAN is to keep costs to minimum and swap Motherboards & CPU 

>From BX440BX/ZX/DX Motherboard having a 
     Intel Pentium II CPU 300 Mhz with 
     256 MB RAM

->To ASROCK Motherboard having a
     AMD SEMPRON CPU 2500 or 2800 Mhz with
     512 MB RAM

I will retain my HD,32 MB AGP Graphics Card, Intel(R) PRO/100 Network
Card, CDRW and Printer. The plus is that I will not have to replace my
300 Watts Power Supply.

My OS is Red Hat 9 with Linux version 2.4.20-31.9

Question to you all knowledgeable people is what do I need to know and
be aware of after putting it together and upon rebooting my system.

Will my present OS be operational on reboot? 
What will I be prompted to do what on reboot?

Can someone let me know what I am getting myself into and be prepared
for what?

Has anyone done this and what were their experiences?

I hope, I have covered almost all my bases and wish to anticipate any
upcoming problems, so any help is appreciated. 

Chris Cz (intermediate newbie)