An invaluable book I have used during my chem eng course at Leeds is Elementary Principles of Chemical Processes by Richard Felder and Ronald Rousseau, 3rd edition. This will tell you how to perform all mass and energy balance calculations that chemical engineers need and provides many worked examples in an easy to understand language. I picked this copy up on ebay for around £15 so hunt around
Perry's Handbook is the bible of chem eng and almost everything is in there (hence the size of it!)
For reaction engineering use:
Octave Levenspiele (rammed full of equations, some explanations)
Elements of reaction engineering, Fogler (big yellow book, very good explanations)
For process control use any really that gives you an understanding of measured, controlled and distrurbance variables, feedforward and feedback loops, transfer functions.
For chemical thermodynamics use Schaum's Outlines, thermodynamics with chemical applications, 2nd edition.
Those should give you an idea of the theroetical side of chemical engineering and the things you can apply it to.