My equipment is just a Canon HG10 and a tripod.
That's all you need, man. Sometimes... but here's a few tips based on that...
For lighting: Try to shoot outside in the daylight when possible... Use a white bristol-board/foam sheet as a reflector... keep it slightly out of the shot aimed under the actor's chin- it's subtle, but important... if your camera can WHITE-BALANCE, make sure you carry around a sheet of 96-bright paper with you and to white balance when you change from natural light to artificial (indoor) lights...
For Audio: Try and shoot indoors for dialog... If you're using the camera mic, make sure it's pointed at who is talking or it'll sound "hollow"... This may mean that you have to do some quick panning during scenes, because if you're shooting each side of the conversation twice and the actors overlap their lines at any point, it'll be difficult to edit the audio... so I'd either do quick-pans and work it into the style, or try and find a shot where both actors can face the camera when projecting their voice.. or maybe one close to the camera and the other in the background, facing the camera....
What's the best way to shoot? I need to shoot at different angles when different people speak... but I tried that before (switching cameras every time I switch angle while the characters freeze) and it's not great... it takes too much time also...
How should I shoot with just 1 camera? Any ideas or experience?
I'd suggest:
1) find a shot where ALL your actors can be in the shot at once... this is your "master" or "wide shot" and shoot the WHOLE scene once (or however many takes to get it right)
2) Run through the scene again, following each individual actor with the camera to get their close-ups.
3) Shoot reaction shots and cut-aways, if you have anything in particular in mind... if you're shooting a comedy, maybe throw some physical comedy or reactions in there to spice it up...
Basically, instead of changing the camera set-up for each LINE, shoot the SCENE in one MODE and then shoot it again in another. If you start with the MASTER-WIDE, the actors will use it as practice, so when you get to the close-ups, they're ready to give it their all. You might even "discover" some great things in your Master shot that can be put in the close-ups more elaborately.
When you edit the movie, if two close-ups don't go together, or if half of one take is BRILLIANT and the other is CRUD, then you can always cut back to the master-wide-shot OR to a reaction-shot/cut-away to change to a different take or shot without any jarring visuals or mis-matched shots.
I was editing something tonight, where my friend is driving... simple stuff, but I only had two shots... one was a side-profile and the other was from the perspective of the rear-view mirror looking at him halfway between a side-profile and a dead-on shot... in any case, the sideway shot and the halfway shot didn't look good when cutting between them because the background would obviously change, and the shots were too similar... thankfully, I had gotten a couple shots of him shifting gears, and by cutting to that shot, I could use both the angles without it being jarring...
Anyway, hopefully that helps you... post it online when you're done! good luck!