Hello and welcome,
You can do a forum search to find info on the topics you are interested in. For example I typed in "valve adjustment Honda", and one of the threads found might be useful to you. There are some very informative older posts by cbxtc6 with pics missing, but links in posts on page 3 have photos for the HCH 1. Keep in mind there are now 3 generations of Honda Civic Hybrid. On page 2 of the thread there is info from Mendel on the second-generation model. The 2004 that you have is the first-generation. There are separate forums here for each generation of HCH:
For advice on getting the most mpg out of your car:
Good luck with your car. So far I am very happy with mine.
Also, check out~