Detect Lies: does exactly that. It isn't as detailed a Psychology, but it will help you spot someone telling you a tale. At +2 you know what to look for while at +8, even the white lies stand out to you. Sadly, this doesn't help your own lying ability.
Perception (Listen): is your skill at hearing. People with high listen skills can pick out snippets of conversation in a crowded room, while low skill people will not notice doors opening and suchlike. At +1 or less, a person is easily snook up on. At +3 they're fairly aware of what's going on, while at +7 they get jumpy when the postman delivers nextdoor's mail.
Perception (Smell): Everyone can smell things, but this skill helps discern what the smell is ("is that cordite I can smell?"). Cooks and chemists may have higher than average levels of this skill.
Perception (Vision): is a person's ability to notice their surroundings. At +2 is kind of average, while +4 means the person regularly spots changes to another person's appearance ("New haircut, Drake?"). Sherlock Holmes? Well, I'm thinking +11 at least.
Psychology (A): this skill allows you to read a target's body language and read between the lines of what they say. It helps you see what they are really thinking. They may be scared underneath, or could be hiding something. The higher your skill the better you are, +2 might let you spot a few lies here and there. At +5 you can see behind most facades, while at +8, no secret is safe as you carefully question and prompt them for their vocal answer and what the really mean.
Track: allows you to track a target by their trail in a rural environment. It is of no use in a city as there is not enough visual evidence to trace them by (also the amount of other people in a city would trample all over it). The referee will decide on a difficulty rating depending on how recent the trail is, the terrain type and how hard the target tried to not leave a trail.