Server Security Tips

[Talrain]

I've noticed there really doesn't seem to be a guide or any information on server security as in preventing very real hacking and not the speed hacking wall jumping type that don't cause any real harm.
Thus I'm requesting some tips on securing a public server from attack. I know Stoneharry some time ago mentioned changing ports from the defaults is a good idea.
Would one basically change the logon and world ports in the configs and make sure they're consistent then open the ports via port forwarding?

Does anyone have any other input and/or tips regarding keeping your server safe from attack? Are DDoS and SQL injections something to be concerned about and is there a way to protect against at least SQL injections?

I'm sure many users would find tips in this department useful so any input is appreciated.

[Thaadevil]

I think you should be most afraid of DDoS if you're server gets big.. (If I understood you right that was what you asked for ^^)

[Talrain]

Well I know what to be concerned about, I'm trying to find information on preventing those things

[Thaadevil]

How to Stop a DDoS Attack

Hope it helps