New language learners often find it hard to decide where to start and who to learn. I recommend to not only use one resource but make use of a combination of resources that suits your needs best. You can for example combine a language class, with a flashcard app or use a German book with an online tutor on Italki.
Applications
Duolingo (free) – You can use Duolingo to build a daily learning practice. There is no work needed from you other than opening the app and following the exercises. You will be able to speak your first words on the first day. To be successful with Duolingo in the long-term, you need to keep using the app on a daily basis. Especially recommended for Beginners!
Memrise (free/paid) – Memrise is the best flashcard application for learning German. You can create your own flashcard sets or use sets created by other students. I found that whether flashcards work for you is highly personal, but give Memrise a try if you like learning with flashcards.
Hellotalk (free/paid) – Practice speaking with native speakers and find language partners easily.
Tutoring
Italki (free/paid) – Italki is a great resource to find language learning partners, get corrections on texts you have written or ask questions. You can also book paid lessons with native speakers ranging from $10-$25 per hour. If you want to sign-up, use my referral link and get $10 for free: $10 Free Italki Credit From Me
Dictionaries (extended article here)
Dict.cc – The best free ENG-GER online dictionary, very popular and good translations
Linguee – There is a new word you have learned, but you are unsure how exactly it is used or how to translate it correctly in this context? Linguee shows you how a word is typically used.
Duden – The most popular and widely used German dictionary (German only). If you are already advanced and are unsure about a word you can search it here.
Reading Practice – German Readers
Huebner Readers – Reading a story in German can be fun and helps you to practice your pronunciation. You can read stories together with your tutor or teacher (Italki is great for this). You can order books by language level and many books can be purchased as .pdf file. The book have illustrations and explanations for difficult words. The readers are starting at €5.49.
Deutsche Welle – DW has many resources such as slowly spoken languages, reading materials and videos from beginner level to advanced.
Nachrichtenleicht – News in German written in easy language. You can catchup with the news and learn basic vocabulary about politics and economy.
Grammar
Reverso Konjugation – Search for any verb and it will show you a complete overview of how it is used with different tenses or how it needs to be modified. Very helpful if you are unsure about why a verb suddenly has a weird new ending or how to exactly spell it in past or future tenses.