if you are having a problem with itunes, cards, devices, etc, contact them and, from my experience, they are very good at responding within 24 hours. http://www.apple.com/support/itunes/contact/
to make a general comment or suggestion to the company- http://tinyurl.com/ItunesFeedback.
request iTunes to make a song, tv show, etc available for download- http://tinyurl.com/Your-Requests
make separate itunes libraries or accounts on 1 pc: in this link, where it says 'hold down the shift key', continually hold it down while clicking the files until the little dialog box opens. http://support.apple.com/kb/HT1589. also, you can use the same credit card or US paypal account to open different itunes accounts if you use unique email addresses or log-in ID's for each account .
you can share music between different itunes accounts if the accounts are on the same pc: http://support.apple.com/kb/HT1203
create an account on iPhone, iPod touch, or iPad (iOS 3.0 or later required).- http://support.apple.com/kb/ht3575
set-up email account for ipod/iphone/ipad: http://support.apple.com/kb/HT4810
sync music: http://support.apple.com/kb/HT1351
sync videos: http://support.apple.com/kb/HT1333
sync photos: http://support.apple.com/kb/HT1678
movies are viewable on Mac or Windows pc using iTunes 7.6 or later, iPhone/iPod touch/iPod nano 3rd/4th gen, iPod classic or on TVs using AppleTV. broadband internet required. you have 30 days after downloading a movie to begin viewing. Once you begin viewing, you have 24hrs left to finish viewing the movie; view it unlimited times for 24hrs. http://www.info.apple.com/kbnum/n307257
create apps: it's costly and time-consuming to write codes for apps. if you don't know how or don't have the money, here's a site that can create your app with no up-front cost. they can submit it to itunes and split the profits with you: http://tinyurl.com/appmaker . if you want to create an app yourself for personal use (not on itunes), you can do that here for free: http://www.buzztouch.com/pages/
close account- you can't do it yourself. you must contact itunes and ask them to disable the account. however, by disabling it, you won't be able to access your downloads. save all your downloads onto a disc before disabling/cancelling an itunes account.
use one account's money for other accounts or emailing a download to someone: you can buy items & have iTunes to email the download link to a friend- or to yourself if you have different accounts. you can't use an itunes gift card balance to gift items- you must use a credit or debit card. you can't use one country's money for a different country's account. if the recipient is in a different country, they need to have a separate account to receive the download.
gift cards: scratched off some of the code? locate the serial number and contact Apple here http://www.apple.com/support/itunes/contact/ and they'll email you the code. serial numbers may start with: GCA & have 16 digits; 60 & have 16 or 19 digits; EPY & have 14 digits; or PBH & have 22 digits.
itunes code generators: there is no code generator for the public to use. if you try those online, it will download destructive viruses to your pc.
re-downloading purchases: http://support.apple.com/kb/ht2519
find missing iTunes downloads: http://support.apple.com/kb/TS1408
back-up your itunes library onto a cd or dvd: http://support.apple.com/kb/HT1382
transfer stuff from your ipod/iphone to your pc: you don't need third party software to do this. it's easy and its free; here are the steps: http://support.apple.com/kb/HT1848
add content to your itunes from a cd or other items in your computer: http://support.apple.com/kb/HT1473
ipod "frozen": http://tinyurl.com/ipodfrozen get a new or used ipod here.
sync new songs without deleting other songs on your iPod: open iTunes, Select your iPod in the Source pane. Click the Summary tab. Click "Manually manage music and videos", Click OK then click Apply.