Kits are usually not the best/cheapest way to go. You will get stuff you don't need. Best way to go is pick out a few recipes from our recipe sub-forum and just buy the flavors to mix those. Get pg/vg, syringes, and bottles if you need them. You can wash out any bottles you may already have and just use those. Just mix in the bottles, no need for beakers or test tubes.
A mixing calculator is a must have. e-liquidrecipes.com is free and works on any computer/phone/tablet, and they have tons of recipes as well. For windows pc
http://ejuice.breaktru.com/ works good and is free.
Also read, read, then read some more. Lots of good info here in the DIY forum and lots of folks here to help.
If you are in the US here are some places to get everything you need:
ecigexpress.com coupon code underground10 for 10% off
bullcityflavors.com coupon code VU6 for 6% off
nicotineriver.com no coupon code except during sales, but good prices.
There are others, those are the three I use.