Well, I'll answer your second question first, since your first question depends on the second.
K Gudi and Bandipur JLR are in totally different places, to get to them you'll have to take different route from Nanjangud (15 KMs after Mysore). K Gudi and Bandipur JLR are both some 80 KMs from Mysore.
Bandipur lies on Ooty road and so is more crowded. K Gudi lies on the way to Biligiri Rangana betta (which has a temple of Lord Vishnu on top). This is not that a big tourist place and hence less crowd.
You can check out details of these two at
Jungle Lodges & Resorts Eco Holidays
I personally haven't stayed in any of these resorts, but have done numerous trips to both these places (i am from Mysore). So no idea on the quality of the resorts. Maybe some others can help you here.
In general i would say that Bandipur is good when compared to K Gudi
Now coming back to your first question...
Bandipur is on the way to Ooty. So when you get to Mysore you'll have to ask for Ooty road. You have three routes to reach Ooty road as soon as you enter Mysore from Bangalore. You'll get the Ring road signal from here you can take a right and head all the way to the dead end of the ring road (which merges into Ooty road). The road is well marked. You'll pass many intersections and two signals. This is the longest route. You'll travel 15 KMs extra on this one.
In the second route, you can take a left at the ring road signal. Then proceed upto Bannur road (where the ring road ends). Take a right, proceed towards Lalith Mahal Palace - Race Course and Ooty road. This is the shortest route and avoids the city traffic as well. I would prefer this route.
The third route cuts right across the city. This is best avoided unless you have dine in or tank up.
Once you are on the Ooty road, you'll get a temple town - Nanjangud. From here you'll need to deviate towards Chamarajnagar, if you are going to K Gudi or continue straight towards Ooty. After Nanjangud you'll get Gundlupet and then Bandipur JLR.
Hope this helps...
PS: Chamarajanagar is the hotbed of the current contorversy.