Give regards to your Chinese friends !!!
Here are some common regards you can use.

新年好
xin1 nian2 hao3
(Happy new year)

过年好
guo4 nian2 hao3
(Happy new year)

新年快乐
xin1 nian2 kuai4 le4
(Happy new year)

恭贺新禧
gong1 he4 xin1 xi3
(Happy new year)

万象更新
wan4 xiang4 geng4 xin1
(Wish u all things take on a new start)

心想事成
xin1 xiang3 shi4 cheng2
(May all ur wish come true)

万事如意
wan4 shi4 ru2 yi4
(Hope everything goes ur way)

And here are some regards you can say to businessmen:

恭喜发财
gong1 xi3 fa1 cai2
(Congratulations for getting rich)

财源滚滚
cai2 yuan2 gun3 gun3
(May your profits pouring in from all sides)

To students:

学有所成
xue2 you3 suo3 cheng2
(May you harvest your studies)

学习进步
xue2 xi1 jin4 bu4
(May you make progress in study)

To politician:

步步高升
bu4 bu4 gao1 sheng1
(May you promoted to a higher position)

官运亨通
guan1 yun4 heng1 tong1
(May you had a successful official career)

SEMOGA BERMANFAAT !!!