The communion books are more than just census Records. They usually cover a 10 year period and list the inhabitants of each farm by family. Usually the first name on the page is the head of the house, followed by his wife and then their children. Below them are hired hands and maids and on the bottom usually lodgers. This varies from parish to parish, but once you familiarize yourself with an area you get used to the books fairly quickly. The names are followed by birthdate and place and where they came from (GB/VK/WK means "old book", meaning they were moved from the previous book to the new one, a year and a page number give you the page in the current book they came from and a year and place name gives you the parish they moved from). Then you have vaccinations, language and reading skills and on the "next page" the actual communion dates. This is followed by notes and finally the "move out" column, which tells you where the person went. This could have NB/UK ("new book") and page number, a death date, a year and page number (for the current book) or a date and a Place if they moved to a different parish. If there's nothing marked that usually means they stayed at the same farm and can be found there in the next book.
If the moving markings were poorly kept, it might be difficult to find people, since the books aren't indexed by name. In the newer books (births, marriages, deaths, moves) they usually list the page number with the event so finding the family in question is easy, but even in the older books they are more than likely to list the farm name so that it's relatively easy to find, especially since most of the books in the database have been indexed by village and farm name. Since the member database has a search function, the easiest way to pull up all the Runola pages is to go to the Kalanti page:
http://www.sukuhistoria.fi/sshy/sivut_e ... p?plid=591
And then type Runola in the search field. It'll give you a list of all the pages that have Runola in the comment column. Naturally this only works with books that have been indexed. To follow moves to different farms you need to open the index for that book (there's a link on top of the page) and find the page that they moved to/from and so on. So to follow Aino Wilhelmina from the last link I gave (shows that she moved to page 466 in 1903) you open the index:
http://www.sukuhistoria.fi/sshy/sivut_e ... ?bid=19523
And then go to image 443 (page 466):
http://www.sukuhistoria.fi/sshy/sivut_e ... 3&pnum=443
There you'll find Aino with her husband and their 3 children (plus the one she had out of wedlock). Similarly, if you want to see where the husband, Juho, came from you'd go back to the index and open page 122:
http://www.sukuhistoria.fi/sshy/sivut_e ... 3&pnum=117
From there you move to the older book, page 643:
http://www.sukuhistoria.fi/sshy/sivut_e ... 2&pnum=602
And so on. I like to follow them all the way to the first communion book they're listed in to make sure that the parents listed in the later books aren't actually stepfathers or stepmothers. In his case here's the first book:
http://www.sukuhistoria.fi/sshy/sivut_e ... 20&pnum=84
In this case the parents really are the ones listed on page 122 earlier. Normally I would check the birth listing in the babtisms as well, but the ones from 1877 aren't online yet (although they have been digitized already, so hopefully they'll be online soon).
I hope this helped a little bit. I think you'll find that Finnish genealogy is extremely easy (as long as the records haven't been destroyed) since pretty much everyone's life was recorded from birth to death with moved and all thanks to the church records.