Shop manual or owners manual? You can find both though the dealership, though toyotas website, and often on eBay. You can also find the shop manual online in PDF format from various "unauthorized" locations (Google it).
toyota dealer I found a web site where you can get a manual for free as long as you join. It is by toyota i got my manual from there. https://auth2.toyota.com/owner/web/page/home I was lokking for the fuse box and this has the whole manual. Hope it helps you!
buy the service manual
You can buy a new, book (paper) version directly from the Toyota website, but they are expensive. I don't know why they don't sell cheap electronic versions (are they really focused on profits from repair manuals??). I bought my repair manual used on eBay for a big discount over new so do some searching. Finally, its totally unauthorized, but if you really search, you can find an electroinc (PDF) version of the echo/yaris repair manual floating around for free on the internet. I believe its technically the 1998 Yaris manual, but its pretty much identical to the 2000-2002 Echo manual although its missing some portions of the real manual.
You can get a refurbished one for about $70. See: http://lmgtfy.com/?q=toyota+echo+mass+airflow+sensor
Depends if you have automatic or manual transmission. Automatic trans fluid is type T-IV, which is a special type made by Toyota, I think I heard somewhere that a 3rd party was selling this type but I haven't seen it personally. You can buy T-IV ATF from the dealership or some online places including eBay at a slight discount.
BUY A HAYNES MANUAL BUY A HAYNES MANUAL
A used Toyota Echo can be easily found at any reputable used car dealerships. Additionally, online websites such as AutoTrader and Motor Trend carry used Echos for sale.
I very much doubt you can buy that on it's own. It usually comes only with a balljoint.
you will have to contact the dealer(toyota)
Buy a grand prix
Buy a Haynes shop manual for 1997-2001 Toyota Camrys. They're about $15.
I would suggest to buy a service manual on your vehicle and then determine on how you want to approach this. Telling you on how and what to do along with the right tools is impossible.