Overclocking AMD Athlon II X4 630 Propus

Hey all,
I'd like to overclock my processor, however, I've never done it before. I've looked online for tutorials, but mostly I'm just finding reviews.

Any tips on how to do it? I tried to increase the Mhz from the stock 200 to 250 in the bios, and I couldn't even start my computer, so I reset it. I saw where someone did that on a review, so I tried.

Please let me know! I've downloaded CPU Z.

My system:
ECS BLACK SERIES GF8200A (V1.0) AM2+/AM3 NVIDIA GeForce 8200 HDMI ATX AMD Motherboard
XFX HD-485X-ZDFC Radeon HD 4850 1GB 256-bit GDDR3 PCI Express 2.0 x16 OCZ StealthXStream OCZ700SXS 700W ATX12V / EPS12V Power Supply
AMD Athlon II X4 630 Propus 2.8GHz Socket AM3 95W Quad-Core Processor ADX630WFGIBOX
Patriot Viper II 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Desktop Memory
Seagate Barracuda 7200.12 ST3500418AS 500GB 7200 RPM SATA 3.0Gb/s
Cooler Master Hyper 212 Plus CPU fan

**Edit: Just realized there was an overclocking forum. I'm new and didn't see it, my bad.