Quick breakdown of my workout:

10 reps ~ 75% max load
8 ~ 80
6 ~ 85
4 ~ 90
8 ~ 80

That's the sequence I follow for each exercise.

My current sequence for my upper body is:

Bench Press (Chest)
Wide-grip Pulldown (Back)
Dumb Bell Press (shoulders)
Close-grip push down (triceps)
standing curls (biceps)

Ok, my problem is, I'm definitely maxing out on my reps as I'm pushing it to the point that I simply can't do another rep, however, after I'm done, I'm not feeling the burn like I used to.

Any suggestions for improving this series?

2nd question, how much time do you give yourself between sets and exercises?

you could add a row - seated cable or bent-over BB, etc - think of your joints in pairs of opposite motions - and shoulders move in several planes : Mil Press+Lat pull down, BenchPress+some Row motion
If you are doing heavy BP - you might want to add some light "pre"hab exercises for your rotator cuff - better now then as rehab

"feeling the burn" is not related to quality of workout or intensity. don't worry about it.

rest btw sets depends on: 1) intensity of the effort and 2) what your training goals are - are you increasing intensity by decreasing rest for example? There is one training program where (for example) you take a 3RM weight, do 3 sets of 2, gradually decreasing rest btw sets over a period of weeks until you are doing 6 reps of your previous 3RM.

if you were doing sets of 3-4 reps at 95% of 1RM you might rest 2-3 mins between sets so that you are recovered enough to do another intense effort. On the otherhand, if you are trying to increase the intensity of the workout, you might decrease rest btw sets.

Probably 60-90 secs would be typical for most types of lifting, or use supersets w/out rest (so you rest as long as it takes to set up the other exercise, do the set and return) or work with a partner - and rest for as long as it takes to reset the weights and the partner to complete a set.

here is a link that describes different workout goals - hypertrophy, strength, power - and the reps, sets. weights & rest typical for each type of workout

http://www.protraineronline.com/past/april1/closer.cfm