I have read on the web that following combination exists :
Proprietary Source code + GPL Source code - > GPL Source code ( All code has to be released under GPL)
Proprietary Source code + LGPL Source code - > Proprietary Source code ( All code remains Proprietary )
Now how does statically/Dynamically linking GPL and LGPL code works with the above combination?
If you want to distribute a combined work, you'll have to use the following license;
Proprietary Source code + GPL Source code
Proprietary Source code + LGPL Source code
See also executing a (L)GPL program from proprietary Source code.
Update (November 2014): A Comprehensive Tutorial and Guide contains a clear an detailed description of the (L)GPL and its usage, including distribution. I recommend it for more details.