good that you used the word "yet".
1) most recorders come with their own onboard preamps. no need to buy another. unless you want high quality signal, then you should get something that has a line input instead (no onboard preamps) at least echo audio / RME / or apogee ($1,2K+/-) if mac. then invest in a great preamp that costs above $1.5-3K. but if delirium90 means you're 22 this year i don't think that's easily granted unless your parents let you take a loan. the zoom equipment we've been talking about costs $400-$600 range all-in-one inclusive. i'm using Zoom R16 myself.
the backing track is up to you, if you do live take, no backing. if you do layered, you record guitars first, then you record vocals separately with your recorded guitars as a backing track.
2) unless you used zoom q3hd/h1 , you'll have to import the .wav from your sd card. or unless you used a minus one (karaoke) track from the internet.
3) editing/mixing can be done on the DAW. though some people with analog hardware mixers do the mixer before that which I don't recommend cos you don't have control from there on. record it raw, then one shot colour/blend/mix it together. systematic progressive.
4)
a) if you're doing live, everything should be live recorded. e.g. iphone film yourself, DAW starts recording, tick tick tick count in, and edit the video to sync with the audio.
http://www.youtube.com/watch?v=18XurAoxqgM <-- this is a good example i did a while back. first part is vidcam's audio, I tried to signal them the sound check is over but they were too engrossed in the headphone jamming so i thought what the heck just start recording.
http://www.youtube.com/watch?v=FvLJyh4lzoE <-- the sudden middle angle = iphone 4 as you can see me filmin.
b) create your master audio track first, then wayang kulit (act) lipsync/guitar strum sync to the audio. if you wanna cover up the off sync much, make sure you don't show the fretboard which you're playing that way just get your strum right + lipsync. instead of your fingers as well.
http://www.youtube.com/watch?v=-eGgnK16OuQ <-- although this is not "wayang" each layered take was videoed down example for the change of bass + guitar solo which had a lot of punch in takes and I was too tired from recording the whole day.(yes the micstands/mics/cables/laptop/audio interface is all portable and brought to the drummer's house.) but you can roughly imagine : properly record the track to metronome tight polished etc, then film an MTV "act" to the music. the only requirements is to play exactly same tempo/style.
so most videos are created audio first. because you can cut a video angle and have the song running but you can't cut an audio off easily unless to fit the video and only if certain circumstances allow.
5) the one I talked about Q3HD > line out > line into your onboard laptop/pc/mac soundcard is the same as "recording under $50 DIY" FAQ which I assume you haven't started reading otherwise you'd have a clear idea by now. what mwwboy mentioned on audio interface = soundcard is covered in my 5 year old outdated but still applicable DIY recording FAQ.
