"再说..." (zàishuō...) is used in a similar way as "In addition" or "Moreover", in that it is adding on additional information or reasons to the topic at hand in Chinese grammar.

Structure
Just add 再说 to the beginning of the second clause of your sentence. Remember that both statements should be related to each other!

Examples

Wǒ bù xiǎnɡ bānɡ zhù tā , yīn wèi tā jīnɡ chánɡ shuō huǎnɡ, zài shuō wǒ yě méi qián.
我 不想 帮助 他，因为 他 经常 说谎，再说 我 也 没 钱。
I don't want to help him. He lies a lot. Furthermore, I don't have any money.