Fishing can be very boring at times, but if you take the time to level up your skill in it, it will be rewarding later on with gold. First thing you should do is buy a lure to improve your fishing rod, which will help you with your skill level to improve fast. The fish will keep getting away without a lure at low levels, so get the highest addition to your pole that you could use. Once you reach level 10 find a way to get to Auberdine in Dark Shore, the fisherman/fishing trainer there will have few quests for you that will give you better fishing rod, with better damage and +3 to fishing. Do all the quests from him and also from the Gnome in the upper room at the Inn. You will get an eventually get a better fishing rod with +5 to fishing.

If you are dedicated you can get to level 150 in few hours, then you get the next level up you will need to find the book, which can be bought from the AU (Auction House). Average price is 3Gold, its much faster than trying to find the seller to save 1 or 2 gold.