Know What You Need
Financial limitations will play a major part in your transfer plans. Quite simply, a club in debt would not be able to spend (major) money on new signings. Finances may impose limitations on any potential targets you have identified and you may need to adjust your plans accordingly. You cannot afford to bankrupt your football club for the sake of signing a good player.
Before signing players, you should also familiarise yourself with the registration & work permit rules of the league/country/competition you are managing in. There is no worse feeling than signing an exciting player only to find out he is ineligible to play due to competition restrictions, or work permit difficulties. You can find the rules in the competition's Rules section. It may seem a trivial concept but ignoring it can be a true sucker punch.