I'm not a big fan of the 209 series manuals with the exception of the 1965 versions. There are just too many volumes. I like the 361 series as its only 5 TMs that cover most everything. Canned message to follow.
Educate oneself by reading the TM.s We have made them available free of charge here on Steel Soldiers. Go to the top, click on resources then scroll down to technical manuals. Once there search for TM 9-2320-361-10 and TM 9-2320-361-20 as starters. Right click on them and save them to your computer for best results. The -10 is the operators and the -20 is the unit maintenance manual. You can also grab the TM 9-2320-361-34, TM 9-2320-361-20P and TM 9-2320-361-34P. That completes that series of TM. All of the 209 manuals are a different series.