Without wishing to start any sort of flame war: Windows user and developers have a different mind set than *nix developers and users. Recommending a *nix tool set to a Windows user is likely to be counter productive in the short term and may not actually offer any real advantages in the long term.

The OP has made a good start in installing Tortoise's subversion client - it's a really nice client that integrates well with the Windows explorer. And that typifies the difference really. Windows is WIMPs oriented. *nix is command line oriented. For most tasks there are equally good tools for both camps that are pretty much the same in terms of the time it takes for an experienced user to get a job done.

On the other hand, if you have the space then installing a virtual machine and running a real *nix is a much better route to take than Cygwin. Especially as there are prepackaged appliances such as Grandma's LAMP which just "plug and go".

As far as Tortoise vs command-line SVN clients, they both have some short-comings. I think that it is important that you learn to use both. Doing that gives you a better perspective on how the other client is supposed to work.

When I first loaded up Tortoise, it drove me crazy because I did stuff that comes naturally in Windows that I would have not thought about doing in *NIX, for example copying an .svn directory to another part of the checkout. When Tortoise kept saying it was broken it was no help when I needed to fix it. When I was using the *NIX client, I learned about more about what I had done to break it and how I could fix it.

I don't think I would have gained that insight if I had just stuck with one or the other. Tortoise is certainly more feature filled but it does not do everything.