@dheerajjoshim
C++ is a free form language hybrid between OO, procedural and some elements of generic templatization. In a sense, C++ can be 100% OO if you want it to, through there are few merits to this. The only procedure you ever need to create is a main(), and even that's possible to avoid if your linker supports defining alternative entry point.
All in all, it's a language designed to balance between power and performance, but execution speed is definitely one of the top priorities of the language, which justifies many of the unique properties that so much irritate OO purists (not that I'm saying, you are one).
wayneface, once you know one or two programming languages from the procedural or OO families, jumping to others isn't going to be much of an issue. Most people rightfully have difficulties adapting to the low level style of the C family when coming from scripting languages, but seeing how you have little if any previous experience, this is unlikely to be an issue for you.
Just like Joe said, C++ has many more merits in terms of power and applicability, which makes it the better choice to advance from C. Another great thing about C++ is it's huge popularity and great user base that you can always turn to if you have problems. Not to mention the great number of open source libraries such as Boost that are available to C++ which will make you far less dependent on API calls and give you more flexibility in terms of cross platform support.
Finally, Obj-C has some advantages over, C++ such as integrated garbage collection and the ability to send messages without expecting response. I have total of 15 minutes experience with it, but it seemed much easier to pick up than C++ ever was. The syntax also tends to be much more abbreviated and full of operators, which may be advantage or disadvantage depending on your own attitude.
If you do decide to go with C++, I advise you to try one of the MinGW wrapper IDEs (Integrated Development Environment) that are available out there. They make coding so much easier than the 'nix-style CLI madness that is nearly unintelligible for new programmers. I personally started with DevC++ which is quite outdated and appears to be abandoned by now. I've heard great things for both Code::Blocks and Eclipse which are free and available for Mac, Win and all 'nix variants you can think of. Give them a shot and see what works for you.