Oracle 10g Nd 11i

well dude, oracle 10g has to with database administration, creation of database, security, troubleshooting, maintainance and all that while 11i on the contrary is a new programe entirely, it has to do with finacials and its the new hotcake from oracle, but the stuff is that most companies recruiting 11i are not as much as 10g, also 10g is cheaper than 11i, i would suggest you do 10g now then later upgrade to 11i if it is ok with you.