The quality of captured wild pets is random. As of patch 5.1, upon entering a battle the Pet Battle UI shows the quality of a wild pet (idicated by a color-coded border around its icon). If you're farming a specific quality, if you forfeit the match your team will incur a small damage penalty (roughly 10%). There is no accurate way to determine a pet's quality prior to the start of a battle.
This guide covers many of the ins and outs of both making money, and spending it wisely. Many players have "secret" strategies for making money that they wouldn't want to put in a public info site, since it gives them their edge in the marketplace. If you can gain the trust of a successful WoW tycoon, you should ask them some of their techniques. However, this guide covers many of the more common strategies.
Guide to Obtaining and Selling the WoW Token Buying and selling the WoW Token, which allows players to buy game time with gold, or make extra gold by selling the token on the Auction House. What is Blizzard (Battle.net) Balance Overview of Blizzard (Battle.net) Balance, a currency used to buy Blizzard Entertainment products including World of Warcraft character services. How to Purchase World of Warcraft Game Time The cost of a WoW game time subscription, how to acquire a subscription, gift one, and cancel it, as well as how to play WoW for free.