Which lens to buy?
I understand the need to stick to a budget, but if I were you I wouldn't waste my money on a 70-300 zoom without stabilization. If you are a beginner, make good use of your 18-55IS, it is a very capable lens. Practice with it till you can afford something like the 55-250 or the Tamron 70-300VC, whicd I had & dropped & broke, but was my favourite lens at the time. Get the Tamron if you can,but in the meantime, practice practice practice with your 18-55. Oh! & don't forget the book.
There are old pilots, & there are bold pilots, but there are no old bold pilots.