PLT ON INST PROFICIENCY FLT LOSES HDG AND ALT AWARENESS WHEN RUMMAGING FOR APCH CHART BOOK.

Narrative

I HAD LOGGED 12 APCHS IN THE PREVIOUS 6 MONTHS; BUT NONE IN THE 2 MONTHS BEFORE THE INCIDENT. DECIDED TO TAKE ADVANTAGE OF AN IFR DAY (900 AND 5) TO GET SOME PRACTICE. THE FIRST APCH (ILS RWY 9R FCM) WENT VERY WELL. ON THE SECOND APCH; ABOUT 3 MI FROM THE FAF AT 3000 FT; I WAS GIVEN A 30 DEG TURN TO INTERCEPT THE FINAL APCH COURSE. I BEGAN SLOWING THE ACFT AND REACHED FOR THE APCH PROCS; WHICH I HAD PLACED ON THE R SEAT. THE APCH PLATES HAD MOVED AND IT TOOK A MOMENT TO FIND THEM AMONG THE OTHER ITEMS ON THE SEAT. WHEN I RESUMED MY INST SCAN; I NOTICED THAT MY TURN HAD INCREASED TO ABOUT 45 DEGS AND I WAS DSNDING RAPIDLY. I IMMEDIATELY CORRECTED THE TURN AND THE DSCNT. SHORTLY AFTER THIS I RECEIVED A CALL FROM ATC ASKING IF I WAS AWARE THAT I HAD BUSTED MY ASSIGNED ALT BY 500 FT. I BELIEVE THE PROB WAS A COMBINATION OF BAD COCKPIT MGMNT AND TRYING TO DO TOO MANY THINGS AT ONCE. THE FIRST APCH WENT WELL BECAUSE I WAS PAYING VERY CLOSE ATTN TO WHAT I WAS DOING (AFTER NOT FLYING AN APCH FOR 2 MONTHS). AFTER THAT GOOD APCH; A LITTLE OVERCONFIDENCE CAUSED ME TO TRY TO DO TOO MANY THINGS AT ONE TIME. THAT IS; THROTTLE BACK; BEGIN A TURN AND GROPE FOR THE APCH PLATES ALL AT THE SAME TIME. THESE ACTIONS DID NOT SEEM TO TAKE A LONG PERIOD OF TIME BUT OBVIOUSLY INTERRUPTED MY INST SCAN LONG ENOUGH FOR THINGS TO GET A BIT OUT OF HAND. IN THE FUTURE; I WILL INTERRUPT MY SCAN ONLY LONG ENOUGH TO ACCOMPLISH ONE (SHORT) TASK AT A TIME. JUST AS I WAS TAUGHT DURING MY INST TRAINING.