How to resize my existing linux os partition size?

[Nicholas Yau]

Filesystem            Size  Used Avail Use% Mounted on
/dev/hda1             5.8G  5.2G  296M  95% /
/dev/hda2              29G  677M   27G   3% /home
none                  125M     0  125M   0% /dev/shm

i have a larger apace in my /dev/hda harddisk.
i need to resize my /dev/hda1 (5.8 gig) to 7 gig.

if i use partition magic, after i resize, do i get error message?

somebody can guide me what tool to use and what which manual to read?

Thanks

Linux folks
Banzai to Linux