Literally, it means "I think that ...". But, it also be used as "I'm going to do ...", or "I'm gonna try doing ...", like that. Chinami used the word a lot for the latter.
I'll supplement shiraga-san's explanation with a few more words. There are cases to make opinion clear in English. In some of such cases, Japanese tend to express it with "I think ~ (omoimasu, 思います)" in Japanese.