So this is just to reassure my self but I'm going to build an office computer and to save money I thought i should just use the I5 2500k with the HD graphics 3000 and that should be good enough for an office computer.
Is that true? can the 3000 handle it?
Yes and yes. Now, many will argue left and right that you need a discrete GPU for acceptable performance and that is simply not the case. Use of an integrated GPU for an office system, doing office stuff is typically the way it is done.
You will be fine and can always add another GPU later, if needed.