puppetdoc: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/puppetdoc - from package: puppet

You may install the required package with command yum install {package}

Error in other languages:
puppetdoc: bevel nie gevind nie
puppetdoc: comandă negăsită
puppetdoc: comando não encontrado
puppetdoc: commande introuvable
puppetdoc: command not found
puppetdoc: käsku ei ole
puppetdoc: không tìm thấy lệnh
puppetdoc: komanda nerasta
puppetdoc: Kommando nicht gefunden.
puppetdoc: kommandot finns inte
puppetdoc: komut yok
puppetdoc: nie znaleziono polecenia
puppetdoc: níor aimsíodh an t-ordú
puppetdoc: no se encontró la orden
puppetdoc: no s'ha trobat l'ordre
puppetdoc: opdracht niet gevonden
puppetdoc: parancs nem található
puppetdoc: perintah tidak ditemukan
puppetdoc: príkaz nenájdený
puppetdoc: příkaz nenalezen
puppetdoc: команда не найдена
puppetdoc: командата не е открита
puppetdoc: 命令找不到
puppetdoc: コマンドが見つかりません