You only need to worry about memory timings if your CPU is not a black edition. If it is not, then you need to change the CPU frequency, at least that is what it is called in my BIOS. Changing that number, unlike simply changing the CPU multiplier, affects the entire system: RAM and Mobo. Thus, if you do not have a black edition, overclocking requires you to fiddle with your memory timings and North Bridge Speed.
I have a Phenom X4 9750, which is not a black edition processor. As a result, when I overclocked it I had to lower the northbridge and up my RAM speed from 800Mhz to 1066Mhz to keep the system stable. I managed to get it from 2.4Ghz stock to 3.0Ghz perfectly stable. Keep in mind I have an after market cooler, the Sunbeam CCF (which I highly recommend by the way!), which kept my temps below 70 at full load.
Also keep in mind that as you increase the Multiplier, at some point, should you decide to push your overclock further, you will have to increase the voltage going to your CPU. My stock voltage was set at 1.2V and I had to raise it to 1.4V to get a stable overclock. You will find that most people do not like to push voltage above 1.5V and for good reason, at some point you WILL fry your CPU, but, so far as I am aware, as long as your temps remain below 70C at full load, you are fine. Just the same, try not to go over 1.5V, just to be safe. You can change your voltage in the BIOS. On my Mobo, the controls are on the same tab as the CPU multiplier and most of the important stuff, you may have to do some searching on yours.
As far as life span, so far as I am aware, unless you OC your CPU to the max, like from 2.6 Ghz to over 4 or something crazy like that (I have a friend that did just that with an Intel chip) the lifespan of your chip will not be affected in any way, provided you don't set the voltage too high
Don't be afraid to fiddle with it. Two months ago I didn't know the first thing about overclocking, but after hours of reading, questioning, and screwing up, I finally managed to get a stable 600Mhz OC, which is pretty good considering the low OC headroom of the 9750.
Good luck!