If you want to learn another language just because, I would advice you to learn any language that has a similar root than yours. In the case of English, it includes many Scandinavian languages and even German (up to a point). It makes learning it fairly easier because the syntax constructions are similar and many words have the same root.
For example, my main language is Spanish, and because of that I am fairly decent at reading and understanding Portuguese if they speak slowly to me, even when I never learned that language formally.
In terms of learning tools, the base is the same for everything. Practice, practice, practice, and don't be afraid to make mistakes. Try watching a foreign movie without subtitles, or chat with someone on their native language (making sure they know you are just learning their language). As I said, don't be afraid of making mistakes, consider than the person you speak with probably has the same difficulties with your home language as you do with his, or perhaps more...
For example, my main language is Spanish, and because of that I am fairly decent at reading and understanding Portuguese if they speak slowly to me, even when I never learned that language formally.
In terms of learning tools, the base is the same for everything. Practice, practice, practice, and don't be afraid to make mistakes. Try watching a foreign movie without subtitles, or chat with someone on their native language (making sure they know you are just learning their language). As I said, don't be afraid of making mistakes, consider than the person you speak with probably has the same difficulties with your home language as you do with his, or perhaps more...