I started learning MVC and the book I have suggests using LINQ.

I've been looking around the web and kept seeing outdated posts with unclear respones saying that Microsoft is going to kill LINQ and that it dosent' support many-to-many relations. 

The application I'm developing has multiple many-to-many relations and I would like to take advantage of relational syntax so I don't need to write extra code.

 Whats the best approach for this? Should I stick to LINQ, and if so, how can I manipulte many-to-many relationships.

Consider using of Entity Framework.

Please have a look at Iain Galloway's article to see how many-to-many relationships can be implemented in LINQ, and some interesting details.

Don't confuse LINQ with LINQ-to-SQL. LINQ is a language feature and can be used with objects, xml, and any number of other LINQ providers. Most definitely DO learn and use LINQ, it's awesome!

LINQ-to-SQL is one of many LINQ providers, and what you're probably thinking of. LINQ-to-SQL can be very useful, despite MS's statements about it's continued development. LINQ-to-Entities is receiving all the attention as far as MS development goes. It is in most people's opinion not 100% yet, but does support many-many relationships better than LINQ-to-SQL. Either one can be used to connect you to your SQLServer database. Since you have lots of many-many relationships you're probably better off with LINQ-to-Entities.

In any case go learn LINQ... it'll change the way you program. Start here: www.linqpad.net