I need to edit a series of basic videos together within the next 24 hours. I have no idea what I'm doing! Please help me.

Here's what I think I need to do:

Phase A
1. Record video #1 in AVCHD-Lite format (this is non-negotiable).
2. Put video into Handbrake - output as mp4.
3. Import mp4 audio into Audacity. Increase volume and reduce noise. Save.
4. Replace original mp4 with improved audio track using YAMB.

Phase B
1. Import photographs into '?' program.
2. Create slideshow (set photo duration etc).
3. Output as mp4 file (no audio needed). This is video #2

Phase C
1. Join mp4 videos #1 and #2 using YAMB with slight pause in between.

Phase D
1. Repeat this process with several short videos.
2. Burn all videos onto 1 DVD using program '?'.
3. DVD should play in any DVD player in the UK (i.e. PAL).

Okay, so here's the software I have at the moment:
Audacity
Handbrake
YAMB
Nero 7

I can't afford to buy any new software right now. Can I get by with freeware and my old version of Nero?

Thanks!