I can't seem to find a detailed breakdown of how to use Flight as a PC beyond what to expect of different maneuverability levels, but whenever flying is mentioned I sometimes come accross mention of checks to fly or stay flying. I have also heard that Perfect maneuverability lets you fly any direction with no penalties, so does that need any sort of check to use? If so, what check is this and in which book(s) would I find more about it?
Ultimately this comes down to triggering a condition, vs the results of that condition.
First, here's the Minimum Forward Speed rules:
If a flying creature fails to maintain its minimum forward speed, it must land at the end of its movement. If it is too high above the ground to land, it falls straight down, descending 150 feet in the first round of falling. If this distance brings it to the ground, it takes falling damage. If the fall doesn’t bring the creature to the ground, it must spend its next turn recovering from the stall. It must succeed on a DC 20 Reflex save to recover. Otherwise it falls another 300 feet. If it hits the ground, it takes falling damage. Otherwise, it has another chance to recover on its next turn.
Good and Perfect maneuverability (and anybody with the Hover feat) don't have a Minimum Forward Speed, and as such can't meet the triggering condition here.
Rules Compendium (p. 145) says this about tripping a flying defender:
A winged creature can be tripped, and if it is, it falls as if it didn’t maintain its minimum forward speed.
This is a new triggering condition. If you get tripped, you treat it as if you didn't maintain your Minimum Forward Speed. Thus, reading the first rule again, the part where it says "If a flying creature fails to maintain it's minimum forward speed" is now true. You did not maintain it (even though you don't normally have one), because the trip rule says explicitly that you failed to maintain it due to being tripped.
Given that, what happens if you get tripped that you fall per the rules on minimum forward speed.
Two things worth noting:
- The rule says a winged creature can be tripped. By a strict reading of that, anything that flies without wings (mostly things with Supernatural flight rather than Extraordinary flight) are immune to being tripped.
- The Minimum Forward Speed rules say that you have to land at the end of your movement, or fall and take damage. Trips happen on someone elses turn, so you have no movement and can't land. The tripping a flying defender rule says that you fall, so the strict reading is that you don't get to try to land and immediately fall 150 feet (and maybe take falling damage). If you don't hit the ground, you can use your next turn trying to recover, as described in the rule.
No, you cannot take 10.
Normally, as long as you are not in a situation of danger, such as combat, or being intimidated, or under stress (like climbing a wall), or being distracted by a traveling bard, you can Take-10 on your Spellcraft checks.
However, as pointed out on this answer (confirmed by a developer), concentrating on a spell is considered a distracting situation and you are not allowed to Take-10 while concentrating on Detect Magic.
Nor you can take 20.
Because there is a penalty if you fail on trying to detect the magical properties of a magic item:
Taking 20 means you are trying until you get it right, and it assumes that you fail many times before succeeding.
Additional attempts reveal the same results.
And the Spellcraft skill does not allow more than one check per day on the same item:
Retry? When using detect magic or identify to learn the properties of magic items, you can only attempt to ascertain the properties of an individual item once per day.