Good on u
davdud101 Usually,
Stand is the first one. Put him in a standing pose and key all bones. Make Pose 2 or 3 frames long. (used to be problems making 1 frame sequences.(a pose) Not sure if there still is, but for me, 2 or 3 frames for a pose has become habit).
Stand pose(s) can have a variety. Like, StandSet is all bones keyed. StandnoNeck would be all bones keyed except neck bone. (so u can reset him to stand, without affecting a neck key which might already be set in scene mode). Theres no end really, Standnohands would be all bones keyed except hands, and so on. These can be handy when you've got something going on in the scene, and just want to reset parts of his body, and not others. You'll come across these situations, and maybe think about 'selected key poses as you get to those situations.
But stand is usually the first pose that i set for a character.
Next for me is usually
Walk. Of course, thats a sequence, not a pose, but stand and walk are used together quite well. (for walking, stopping, walking again....)
After that, it usually depends on what you need going on in the scene.
If you wanted him to go from stand to sit, you'd make a sit pose. Then In scene mode, you need to add stand pose. Then copy all stand keys, (select figure to select all keys), and paste to the frame where you want him to start to sit, so that theres no 'drifting' before he actually starts to sit down. So then you add the sit pose a few frames after the ones you've just pasted.
Tweaking in scene mode is often required.
Things to watch, when copying all keys, to paste at an end/start point, is the position and orientation keys. They become relevant depending if position and/or orientation need to be kept or changed at the moment.
'Set' keys are also a handy thing. eg: in a new sequence, pose just the hand(s) into a comfortable position, and then key only the hand bones.
Then, you can add that pose at anytime in the scene, just to get his hands back to a decent pose. Really handy if you start getting in a bit of a mess in scene mode, and just want his hands back to normal.
Ideally, you want a mixture of poses and sequences, and also to be animating in scene mode as well. (tweaking between poses, doing other movements not posed in sequence) With time, you get in the swing of it. My most 'interchangeable' sequences involve: A 'walkLegsOnly' sequence, (key only leg bones). Then i have several upper body sequences, throw ball, wave, Armsswingnormal, Armswingwild, hands on head etc, so he can do all these things while he's walking. AND a heap of HAND POSES to mix with the sequences.
Good luck. Happy to help where i can.