Ipod Touch Won't Sync To Itunes

Here's my story. Please let me know if you can help.
I purchased a 4th generation Ipod Touch, I plugged it into my computer and It said I needed the version 10.5. or later, so I went and purchased the new version of Mac OS X Snow Leopard 10.6.3.
I installed it, and I updated my itunes, and my internet browser I updated safari, it told me I had to restart my computer once it was finished, so once it finished I pressed restart. While that was downloading I had my Ipod plugged into my computer and it was working in itunes, I was putting music onto it. But once safari finished It restarted my computer, then once it turned back on my internet wouldnt work, I have been having troubles with my internet in my room, not sure why because my wireless internet is just in the other room. But it is working now, but I don't know how long it will work. Anyways, so I clicked on itunes and plugged my ipod back in and nothing happens. It doesn't come up in itunes at all. I am not sure why this is happeneing because It just worked, before I re started my computer. Is there a way to fix this? Someone please write me back! HELP ME PLEASE!