My husband was looking up his lineage and found the abbreviations of PS and STB after some. What do they mean?

Question

Ex. Willaim A. McGuiness, STB and Trifena T. Walker, PS. Both are Ireland descent.

Answer 1

STB means "said to be", meaning that a claim was made but that documentary evidence is lacking.

PS means Patriotic Service.

Answer 2

I haven't heard of those - perhaps you should post in Genealogy, under the Arts & Humanities category. You might get more responses.

One possibility for STB:
Sacrae Theologiae Baccalaureus, or Bachelor of Sacred Theology

Obro is right - I found this article that explained the concept of STB:
http://ancestry.com/learn/library/article.aspx?article=5427