Q: what if it doesn't give me an option for a software update on my ipod?

That is only a feature of iOS 5 or later...

If you have iOS 4... See Here...

http://support.apple.com/kb/HT4972

OR...

Connect to iTunes on the computer you usually Sync with and “ Check for Updates “...

If an Update Appears Install it...

if not... you are up to date for your particular Device...

See the Using iTunes Section Here...

How to update your iPhone, iPad, or iPod touch

Go back to the article you asked this question from, ignore the instructions for updating it wirelessly, scroll down, and follow those for updating it from iTunes on a computer.

(82035)

To update

The Settings>General>Software Update comes with iOS 5 and later.

Connect the iPod to your computer and update via iTunes as far as your iPod model allows

iOS: How to update your iPhone, iPad, or iPod touch

A 1G iPod can go to iOS 2.2 via iTunes and iOS 3.1.3 via

Purchasing iOS 3.1 Software Update for iPod touch (1st generation)       

https://buy.itunes.apple.com/WebObjects/MZFinance.woa/wa/touchLegacyLandingPage

A 2G to 4.2.1. Requires iTunes version 10.X. If a Mac it requires OSX 10.5.8 or later. With OSX 10.4.11 you can only go to iTunes 9.X which gets you as high as iOS 4.1

A 3G to 5.1.1  Requires iTunes version 10.5 or later

A 4G to 6  Requires iTunes version 10.7 or later. For a Mac, that requires a Mac with OSX 10.6.8 or later

Identifying iPod models