The specific dialect of English that you learn is often chosen for you if you are taking classes, but if you are trying to learn on your own, you get to do the choosing. American, Canadian, British, Irish, Australian, New Zealand, South African, or any other English dialect is fair game, though you might find more resources for American and British English than for other types, if you do not reside in those other countries.
It's unusual to find books on learning Australian English in the United States, for example, unless you do a lot of research. Whichever dialect you choose, however, stick with it. If you mix dialects, you won't learn consistent grammar, punctuation and spelling.
Many use a combination of methods to learn English, but studying books is very common. Sometimes people will just use a book, or they’ll get a combination of a book and an audio program.
English pronunciation varies from the spelling in enough instances that not getting an audio program can lead to an inability to pronounce what you read. Having the audio component is crucial for both your pronunciation and comprehension, so look up English videos in your chosen dialect so you can practice and better understand the language.
Some programs only offer audio help. These are a helpful component because they force you to listen and comprehend. But if you use only audio, you’re not going to get assistance with spelling or reading, which is crucial in learning English. Since English does not have a one-to-one sound-letter correspondence, you must have resources that cover reading, writing, spelling, listening and so on.
Conversation is the best way to get comfortable speaking and reading English, but classes often concentrate on just the sentences in the book. Get a language exchange partner, or better yet, if you are not yet in an English-speaking country, visit or arrange to study abroad.
If you are already in the United States, for example, arranging for conversational language with someone who wants to learn your native language can help you become more comfortable speaking in a casual manner.