I started learning Mandarin few years ago myself and have found these resources to be quite helpful:
Learning Chinese Online Page – a great website with lots of free online resources;
http://www.nciku.com/Online English Chinese Dictionary, Learn Chinese Mandarin Online – a website with Chinese-English and English-Chinese dictionary with Chinese handwriting recognition, pinyin translation, audio pronunciation, personalized vocab lists, picture etc.
Free online mandarin audio courses – offers some basic Chinese dialogues and resources, learn Chinese pinyin, slang, calligraphy, and some other Chinese basic knowledge or skills.
BBC – Languages – Real Chinese – BBC Chinese learning program;
Learning Chinese 学汉语 – China.org.cn – a great website to learn Chinese;
MDBG English to Chinese dictionary – an online English-Chinese dictionary and also allow people to take quiz or create flashcards;
Log in – Memrise – an online language learning website which helps learning Chinese characters;
Livemocha – online language learning community;
Chinese Garden – a good website for beginner students;
Learn Chinese · Study Chinese · ChinesePod – a Chinese learning website with classes, news and podcast;
Teaching and Learning Resources – Chinese learning resources and games;
Resources for Studying Chinese – forum about how to learn and teach Chinese;
Confucius Institute – Confucius Institute online;
Shanghai | CNReviews – website for Chinese culture and top news headlines;
FSI Language Courses – Public domain versions of language courses from the Foreign Service Institute.These courses were developed by the United States government
—————————
Good Luck