Sri Nama-mala-grahana-mantra
(upon taking one's beads):

tribhanga-bhangima-rupam venu-randhra-karancitam
gopi-mandala-madhya-stham sobhitam nanda-nandanam

"His form bent in three places, His hands bent over the holes of His flute, the son of Nanda Maharaja stands resplendent amidst a circle of gopis."

Sri Nama-mala-grahana-mantra
(on taking the beads for the purpose of japa [japarthe]):

avighnam kuru male tvam harinama-japesu ca
sri radha-krsnayor dasyam dehi male tu prarthaye

"O Mala, please destroy inauspiciousness in my chanting of the holy name of Lord Hari and grant me the position of service to Radha and Krsna. This is all I pray, O Mala."

nama cintamani-rupam namaiva parama gatih
namnah parataram nasti tasman nama upasmahe

"The Holy Name is a beautiful transcendental touchstone--it is the supreme goal. There is nothing higher than the Holy Name. I therefore worship the Holy Name."

Sri Nama-mala-samarpana-mantra (consecrating the mala); traditionally, Vaishnavas first offer Krsna everything they use, including their neck beads, japa beads, etc. I don't know that this is intended here though.

nama-yajno mahayajnah kalau kalmasa-nasanam
krsna-caitanya-prityarthe nama-yajna-samarpanam

"The sacrifice of the name is the highest yajna, which destroys the contamination of Kali-yuga. In order to please Lord Sri Krsna Caitanya Mahaprabhu, I offer this sacrifice of the holy name."

Sri Nama-mala-sthapana-mantra
(establishing the beads):

patita-pavana nama nistaraya naradhamam
radha-krsna-svarupaya caitanyaya namo namah

"The holy name is the saviour of the fallen. Oh, please deliver this lowest of men. Obeisances again and again unto Sri Caitanya Mahaprabhu, unto Sri Sri Radha-Krsna."

tvam male sarva-devanam sarva-siddhi-prada mata
tena satyena me siddhim dehi matar namo 'stu te

"O Mala, among all of the gods, you are considered the bestower of all perfection. By dint of this fact, O Mother, please grant me perfection. Obeisances unto you!"