The page called "transfers" contains a list of players available for transfer either through free agents, local clubs, foreign clubs or non-simulated ones (f.e. called "minor foreign club"). The transfer window is open from beginning of each season until the end of league round 12 (it is marked in your fixtures list). During that time you can sign any player that is present on the transfer list and is willing to join your club.
The list is different when you visit it without having scout among your staff and with one - scout uses his connections to find more available players. Also player can be transfered only once each season, so if he was transferred already this season he won't appear on the list any more.
Once you click on player on the list the basic informations about him and potential transfer will appear. Unlike other games in SMFC Online is limiting the data available about the player - like in real life the player is complete stranger to you and you have to make decision based on limited knowledge about him.
You can use additional option to gain some informations - invite the player for one day tryout or send scout to gather some info about him, but those options are not always available. For example older players will be reluctant to take part in tryout, while players from obscure clubs or free agents will not be available for scout report.
The scout report and tryout report are also a bit enigmatic on purpose - you can gain some insight into player abilities, but you won't see all his parameters before actually buying him and getting to know him.
Once you hire a scout you can use him to find local amateur players by selecting the position and age of the potential player. Potential of amateur players is usually very low, but they are very cheap and are available at any time during the season (even after transfer window was closed since they are not professional players).
Amateur players are meant to be the last resort to fill the gaps your team might have due to injuries or other problems, also they are available even when you are in the debts.
You can also send your scout to any of the available foreign countries. It will take him some time to come up with findings, but you can give him a bit wider guidance, for example you can send him to look for offensive players (midfielders, wingers and attackers), defensive players or even to look for player on any position. Of course more specific guidance means he will need more time to find suitable players for you.
On the other hand during the time he is abroad he can't do any scouting for amateur players. Another drawback is that you can hire foreign players, just like domestic pro players, only during the first half of the season. Of course you can scout any time during the season, but you can only sign new player during transfer window.