Here is a list of tutorials about Linux in general, with some about security in linux. I found these links in one of the Facebook Groups.

I hope that you’ll like them and if anyone needs me to make a tutorial for something particular, please don’t hesitate to ask.

1). Installing Ubuntu Using VirtualMachine )

2). Introducing Ubuntu 11.10 )

3). Compiz in Ubuntu 11.10 & 10.10 ) )

4). Blocking Ports in Linux using IP Tables )

5). Beginner guide.

How to install applications using Ubuntu Software Center and the Terminal )

6). Using CHKROOTKIT and RKHUNTER to detect Rootkits ( Basic Overview )

7). Using BeEF to Hook Browser & how to protect yourself from XSS attacks )

8). Learning about, configuring and compiling a kernel. )

9). How to Cyanogenmod 7 on Samsung GSII Using Ubuntu 11.10 )

10). How to root Samsung GSII using Ubuntu 11.10 )

11). Control your Android using VNC )

12). How to configure WakeOnLan in Linux-Ubuntu )

13). SMT Management Series.

How to Static IP using Terminal )

14). SMT Management Series.

Introduction to NTOP ( Traffic Analysis ) )

15). SMT Management Series.

Encrypt your files with ENCFS )

16). SMT Management Series.

Linux File Server with Samba )

17). SMT Management Series.

Backup server with Clonezilla as Image )

18). SMT Management Series.

Creating Virtual Machines in a headless machine (VBoxHeadless) )

* Please note that the videos about Android are for educational purposes only.