Simple editing can be done with HD Writer AE 2.1 and newer. It comes with
Panasonic TM700 (free for its owners).
For advanced editing you may use
Adobe Premiere 4 and newer, Sony Vegas 9.0 Pro and newer.
All conversions are mainly suggested by spammers. It is not a good idea to convert and loose quality. It is better to either get another camera or other software.