Howdy
IT major hmm... Honestly employer will see you as a generalist "using" technology - able to do some sys admin, coding, analysis - a bit of everything.
Yet since there are so many areas of IT which area should you focus on? For me right now, I would choose any one of these: a) big data/ data analysis/ DBA/ business intelligence/ data warehouse, b) security (netowrking, system, web), c) SOA/ cloud computing and solutions (
Java, .NET, programming stuff).
Now looking a bit deeper, doesn't what route you choose
you should learn the basics of the following:
common commands of Linux/UNIX
TCP/IP networking
design and work with databases (eg create tables/views, normalization, SQL)
comfortable with at least one programming language and design
patterns
security terminology (eg firewall, port forwarding, DMZ etc)
server and storage sizing (what hardware to use for such and such project)