adding partition.. how ???

I have redhat 6.1 and win98 on my PC.
I need to have more space in lunix (I underestimated the size I would need when I installed it).
I have added a new partition using partition magic in win 98 and made the type linux. How do I tell linux to use the new partition ??

I have been through all the FAQ’s and docs I could find but cannot find the solution.

Any ideas ???