Hi all, I am a noob in oc things, soo I'll need some help from U.

Here is my specs

Sempron 2400+ stock HSF
Abit NF7 V2
Ati Radeon 9250 128 MB 64 Bit
80 HD Seagate
Kingston Value Ram 2x256 Dual Channel CL 3

Currently my Sempron running at 190Mhz x 10 = 1.9 Voltage 1.6 V Temp 47 C at idle and 52 C at full load
I am able to push until 210 Mhz, but I decreace it to 190 Mhz ( cause I am using Box HSF).

My ATI running at 66Hz ( anyone now what is this ?) I saw it inside the bios. What will be the result if I increase it ?
I oc My ATI from 238 Core, to 250 Core. ( Do I need VGA fan ? to increase it to 350 ?) The memory it self running at 210.

For the memory I am planning to run my RAM at 2.5 CL.
Can I do that ? And what I need to do to increase it to 2.5 CL ?
I saw some RAM settings in my bios, about the CL and etc.

My bios driver is the lastest one

there are 3 main OC questions. CPU, VGA , Memory.
Thanks A lot