How to get my iphone 3GS Jailbroken?

I have Iphone 3GS Updated 6.1.3
i want to jailbreak it and i want that cydia app:-/ but have no idea how to do this. My first experience with apple:-/ help?

1. Download the latest iTunes and upgrade your iPhone to ios 6 through itunes. If this works skip to step 4

2. If upgrade does not work, download ios 6 (link below) and than Put your iPhone in DFU mode (Google if you need instructions).

3. Once in DFU mode, open iTunes and hold shift(Windows), Command(Mac) and point to the downloaded ios 6 firmware. This will give you ios 6. I had errors updating through itunes and itunes restore worked for me. If you can update directly through itunes that will work too.

4. Once iTunes is done restoring, connect your iPhone into your computer and open the latest version of redsn0w. (Link at bottom).

5. Once in redsn0w select jailbreak, and it will ask if your iphone is new bootrom, make sure to correctly identify.

6. Put your iphone in DFU mode for redsn0w to detect it.

7. After it has been detected, you want to check jailbreak and also install iPad baseband (since the baseband right now isn't unlockable)

8. The process will begin and since this is tethered jailbreak after it is done you will need to go back into redsnow and select just boot (while your iphone is in dfu mode).

9. Now that your iPhone is jailbroken and tethered booted, launch cydia.

10. Once in cydia, go to manage than sources.

11. Now select edit than add, and type "http://repo.iparelhos.com" than hit add source.

12. After the source is added, search for ultrasn0w fixer and download it.

13. Next in cydia search for ultrasn0w and than proceed to download that as well.

14. We will now downgrade the iPad baseband. Open redsnow with your iphone connected and select jailbreak.

15. Put your iphone in DFU mode and this time only check downgrade ipad baseband. Nothing else! Reboot tethered once again and your done!

Dude. I have really very bad experience for iphone 3G upgrade. And sincerely speaking first Google that what is tether, semi-tether and untether jailbreak. And for your kind information I'm searching for last 3-4 months for untethered jailbreak. But there's no successful untether jailbreak available for 6.1.3 till now.

If you still want to go with untethered jailbreak than I suggest you first downgrade your iphone 6.1.2 than jailbreak it is more safe than 6.1.3.

You should ask somebody who is special to do it for you. It is easy to damage it.