PeridexisErrant's Starter Pack bundles Dwarf Fortress with huge community upgrades - graphics, tools, bugfixes, and much more.

It's suitable for anyone - if you've never tried DF before, or played for years. For beginners, everything is bundled and set up for you; any setting can be safely ignored and the default will just work. For advanced players, everything is open: customise, add, remove, update, or replace anything you want to. The Starter Pack means you can spend hours setting up your fortress, instead of your DF install!

There's a thread on the Bay12 forums for feedback, questions, suggestions, or anything else about the pack. The second post has a complete table of contents, and recent changelogs.

Besides this official download page on DFFD, /u/Hecknar maintains df.wicked-code.com, which mirrors every release since 0.40.01! The final 34.11 pack is here. The final 40.24 pack is here. The final 32-bit pack, 0.43.09-r09, is here. The final 43.05 pack is here. The final 44.12 pack is
here. If you need an older pack or that site is down, let me know and we'll sort something out. OSX and Linux packs are available at http://dwarffortresswiki.org/Lazy_Newb_Pack

INSTRUCTIONS:
1. Download and unzip the folder
It's a bundle of portable apps; there's no further installation procedure.
The pack must be able to read/write files though - so don't put it in a "Program Files" folder.
2. [Optional]: Use this tool and the checksum on DFFD to confirm you got an uncorrupted file.
3. [Optional]: Upgrade from an earlier release by copying your old 'Dwarf Fortress 0.xx.yy/data/save/' folder to the new pack.
DO NOT try to upgrade by extracting or copying over an earlier pack.
4. [Optional]: Visit the DF wiki or my tutorials for help learning to play.

Finally, an appeal: Dwarf Fortress is free, and redistributable, because Toady lives off donations. You can support Bay12 Games here. Even if you decide not to donate, Dwarf Fortress is still free - and so is this unofficial pack.