The operating systems, languages, and tools you need to learn depend on the area of information technology you aim to specialise. For example, you may specialise in Web technologies, Internet technologies, or e-Business technologies, Mainframe technologies, Data warehousing technologies, Mobile communication and wireless application technologies, CTI & Voice enable technology, Object oriented analysis & design, Embedded technologies, etc. These technologies are learnt best on the job. Most of the IT software and services companies train fresh candidates on the technologies they are using. But if you still want to learn before trying for a job, first decide the technology in which you would like to specialise. In my opinion, it could be a good idea to learn web/Internet/e-Business technologies like C++, VC++, Java, Advanced Java, ISP, EJB, CORBA, XML, Perl, VB, ASP, MTS, IIS, and distributing computing environments (COM/DCOM). Since you have already learnt C, C++, and Core Java, concentrate on learning the other languages and tools given above.