Alhamdulillah there are some great Arabic learning resources available online.....here is a small list of a few I have come across.
Some nice printable resources for children to help teaching Arabic - you'll find stories, colouring pages and themed vocabulary curriculum.
If you are learning the Madina Arabic books, this is a useful site to help you, with audio sounds, and end of chapter quizzes!
A free online resource which helps you to learn the Madina Arabic vocab bi'ithnillah.
-note this site offers courses on virtually anything and everything....so I am not recommending this whole site, rather this particular course.
I came across this resource quite recently so I have only skimmed through it - however it looks a great addition to the Madina Arabic Reader books (The Madina Arabic course in a child-friendly version).
It is packed full of extra colourful lessons to help practice the vocab and grammar understanding all presented in a nice simple and colourful format.
I don't know anything about this site, but this particular resource looks hugely beneficial inshaAllah.
Lots of nice kids learning resources available for your to print at home.
The Taalibideen Jr family of websites offer great education resources!
I think right now the Arabic site is not available I assume for maintenance, but I have linked the Islamic Studies site which has a link to its Arabic sister site in the menu bar so inshaAllah, when its back online it will be easy for you to find.
A huge series of step by step video lessons, which start from learning the alphabet up to rules of reading the Qur'an.
I have included this site in the list, because I know there are many parents who have come to Islam as adults and are learning Arabic inshaAllah.
While this site does not substitute the role of having a real teacher, it is a great help for those who perhaps can not find a teacher easily or want to have extra independent practice.
I don't know who is behind this site and what they are upon, however from what I can see this free resource is just helping you to learn to read the Qur'an with some rules bi'ithnillah.
Here are 2 more sites I've come across, but haven't got time to put them into graphic images!
An excellent resource teaching Arabic grammar right from the beginning in a series of easy to follow readable lessons.
This isn't a free site, but I have tried it and it is unlike any other Arabic teaching website. Read my review for full details in this post inshaAllah.