What are you looking to spend to get started?
What (if any) gear do you have already?
If you wanted to start small and simple you could get something like the
MXL mic mate or for a little more the
Shure X2U looks like it has a lot more features and control. Using either of those will give you an XLR to USB 1 channel interface that will work with any microphone or you can record your bass direct using a DI box (on the cheap you can get a Whirlwind or something, but investing in a Countryman Type 85 or Radial JDI is better for the long run... someone has a JDI in the sale forum for $120 right now).
I don't think either of those includes any software, but for starting out Audacity is a decent freeware choice. Another great free (or close to free) option would be
Reaper, though it'll have a bit more of a learning curve early on.
When you want to expand to something more advanced, there are definitely an overwhelming amount of options. Keep in mind that the latest and greatest things out there are generally not much better than older versions of the same thing. You can get older rigs for a fraction of what they cost new so you can get an 8 channel interface for well under $200 if you shop around. If you need more than 8 channels, or think you'll want more than 8 down the road, be sure to look for something with ADAT inputs and outputs so you can get something like the
ADA8000 (probably the only Behringer product I'd ever recommend to anyone) to expand on it.
If you find yourself in need of preamps, small format mixers are the cheapest way to get a bunch of decent preamps. Mackie's generation old VLZ Pro boards had decent pres and ca be found used for decent prices now (a 1604 VLZ Pro for $400 = $25 per preamp... even the crappiest standalone preamps cost more than that).