With no real primary scholarship on the NWT committee, I'm guessing that the gang made use of the same tools you mentioned, concordances, lexicons, etc. Then they had to have dozens of translations to refer to. With said tools in hand (no pun intended), I'm guessing Franz & company proceded to cherry-pick the verse translations most favorable to the WT worldview. Hell, anyone with the time and desire could probably put together their own translation that way. You certainly wouldn't need any real knowledge of Ancient Near East languages, society, etc.
On the other hand, a real, credible translation will involve maybe dozens of collaboraters, all of whom would have doctorate degrees in the appropriate fields. Plus a good set of writing skills, to make the translation enjoyable to read, or at least bearable is a big plus. I don't consider the NWT to be very readable when compared to the other English bible translations. I especially enjoy the New Living Translation update for reading, and the Holman Christian Standard Bible for studying and reading. The NET Bible has an amazing set of translator notes to let you see how they came to their decisions. If you want YHWH in your Old Testament, the aforementioned HCSB is good. It uses Yahweh when the biblical text emphasizes Yahweh as a name: "His name is Yahweh" (Psalm 68:4). However, don't expect to find it in the NT, as in the Jew World Translation.
For your Bible studies, I strongly suggest getting some Bible software; you simply won't believe how helpful it is. If you haven't tried this already, I suggest trying out a free (but very professional) software title called theWord from www.theword.net. I use it. Once I realized how great it was from using theWord, I got WORDsearch9 (at www.wordsearchbible.com). It has lots of the resources you are looking to collect, and if you are careful this can be had very reasonably. Finally, if money is not a big object, try Logos Bible Software (www.logos.com). It's the best I've tried, but a bit pricey, as I mentioned.
Another good tool in Bible study is the "Study Bible". These come in all kinds of versions and formats. The most comprehensive I've found is the ESV Study Bible; get it at a book store that carries bibles, or online at Amazon, or anywhere, really. For the best price on the ESV SB, I got mine at www.wtsbooks.com. Good luck in your learning journey.