1. Farms are generally listed by rote (district). In eastern and northern Sweden it was common to list farms clockwise (solskifte). Some parishes listed alphabetically. Some listed in a mysterious fashion, the reason known only to the vicar.
There is no simple answer that covers all of Sweden.
2. The head of household is listed first. Everybody else is in relation to him (or her, if a widow with no legally competent children). E.g., mother (mor) would mean the head's mother - even if the farm is the wife's. Be aware that several farms may have the exact same name - most often it's a question of a cluster of farms, a very small sort of hamlet.
The owner of the farm can be listed at the top of the page, e.g. Eg. Jon Andersson, Vasslunda No 3 - owner is Jon Andersson at Vasslunda No 3 farm (in the same parish, otherwise the parish is stated).
3. Seasonal workers were never listed, only permanent workers. You had permanent farmhands, hired for one year at a time, and you had a local worker-pool. The local worker-pool was made up of people living in nearby crofts or cottages; indeed the rent for a croft was paid for by a set number of days working for the farmer renting out the croft's land. Farmhands registered at a farm were needed throughout the year while work-peaks were covered by people from the pool (just like today).
If you have a farm with one or two male farmhands working at the farm simultaneously and two or three female farmhands also working there simultaneously, you're looking at a big farm (you have to look at the moving in and moving out dates for the farmhands to see how many were there at one and the same time).
There is no telling how big the farm was. The basic measurement was mantal (also called hemman) but this cannot be translated into acreage; one mantal was what was locally decided in the 17th century could provide for one family and also pay full taxes. This means that in the south a farm of one mantal could be less than half of a similarly determined farm in the north. Also, agricultural tools, methods, seeds, organization improved so much that a farm of e.g. 1/8 mantal in the 19th century would yield much more than a farm of one mantal in the 17th century.
4. At the top of the page can be listed anything the vicar wanted to list. Some places it was a farm name, other places it was the rote (district) name, some places it was the village name. Or something else.
Since the arch-bishop isn't boss but primus inter pares (first among equals) there was no standardization regarding how to write records between the dioceses - indeed, no absolute standardization even within a diocese - until the civic authorities decided on standardization in 1860. Even then standardization was compulsory only for the excerpts that were delivered to central authorities.
5. #19 Väng and #20 Väng weren't only different farms, but most often different clusters of farms, crofts and cottages. From the names I infer that this is Skåne province; my mother's family comes from Skåne and at least in the western part of Skåne a name like #19 Väng could easily mean two or three regular farms, a few crofts (in Skåne the term gatehus is commonly used, not torp as in most other places in Sweden) and some cottages, usually with craftsmen - also perhaps a hussar and his family (making the farmer a rusthållare, a person who supports a cavalryman and his horse in return for tax rebates).
6. Serious non-fiction books about the condition of life in Sweden in the 1800's are hard to come by in English. For fiction I cannot recommend books by 20th century writers such as Vilhelm Moberg, Ivar Lo-Johansson, Harry Martinson, Moa Martinson, Eyvind Johnson, Per Anders Fogelström, Jan Fridegård etc. as reading for finding out about general conditions of life in Sweden in the 1700's and 1800's since they all focus exclusively on what was bad in the old days. There's no denying life was hard for many people but these authors had a particular political agenda while e.g. contemporary visitors to Sweden paint a far more balanced picture. Quite a number of these visitors to Sweden wrote diaries, letters and reports which have been published, many in their original language, in some cases English. There is e.g. a book by Mary Wollstonecraft, Letters Written in Sweden, Norway, and Denmark from 1796 which to some extent deals with what she found out about Swedish social conditions on her trip here.
Here you can find some papers on life in Sweden:
http://web.comhem.se/~u31263678/genealogy/ - these papers are used at courses held by the ethnological department at Göteborg university.
7. The contract was usually for one year (it could, particularly in the south and in towns, be for six months). Until 1833 the year ended at Michaelmas (Sept 29th) but was then changed to October 24th. In the country you then had seven days to move into your new job, meaning the year started on Nov 1st. The intervening week was thus a holiday, but you got no pay (including no food, no free lodging) so the week was often referred to as slankeveckan, slim week.
Your employer couldn't fire you during the year - unless you committed some crime like stealing from you employer. In law, you couldn't quit either, but in practice all but the most rigid employers accepted a substitute worker if you arranged for one - e.g. a sibling or a cousin - who of course had to be as experienced as you were. When you left an employer you had to obtain a so-called orlovssedel, a paper that stated that you had left your employer in a lawful way.
Farmhands quite often had a very strong bargaining position and managed to obtain much more than minimum wages - we know because there were numerous court cases due to the fact that one or the other of the parties felt they had been cheated.
Farmhands had to be 15 and be confirmed. Before this they could serve if the family was very poor; they then worked only for food and lodging and perhaps, if they had a kind mistress, some cast-off clothes. These very young servants are usually noted as gossen (the boy) or flickan (the girl) in the church records (not drängen/pigan). When you turned 15 and was confirmed, you were a proper farmhand and was protected by law.
It must also be noted that it was compulsory to have a job; if you didn't you were picked up for vagrancy and put to work in a work-house. And you couldn't wander around the countryside at will either, you had to have what amounted to a domestic passport.
Ingela