You need a good few months to work through any of the study guides, although some are longer than others.
If it is your first time studying this way, it is easy to be daunted by the length of these study guides. One way to work through them is to break them down into smaller chunks. If you choose chunks of 5 pages per study session, a 230 page set of questions and answers (for example Lumatul Ittiqaad) would take under a year (46 weeks) to work through.
Each session, you can work through those 5 pages two of three times over. By the third time through, you will know the information well inshaa Allaah, so the next week you can move on to the next 5 pages.
If you are listening to audio lessons that the Q&A accompany, then these are all roughly the same length (normally around 45 minutes), and you can stick to one lesson per study session. At first, it may seem a little unambitious, but consistency is what is important. Increase it only if you can manage one audio lesson per week.
“The deeds most beloved to Allaah are those that are continuous, even if they be small.” (hadeeth, reported by al Bukhari, Book of Eemaan) so do not be put off by doing things little by little, so long as you are regular – the same hour every week, week after week.
Before you realise it, you will have actually covered a great deal of information inshaa Allaah. You might consider dedicating certain sessions for revision, perhaps every fifth lesson.
I would be interested to hear of your experiences of studying, both the things that worked well for you as well as the things that did not work so well, so that we can all learn from that inshaa Allaah.
May Allaah, the Perfect and Most High, enable us to learn His Religion, act on it, call others to it and be patient upon doing that – aameen.