I have a Maytag Neptune Dryer. The clothing is not tumbling. It's sticking to the sides and takes long to dry. It almost seems as if 1 of the 3 flaps should have been slanted. Or it's spinning too fast.
Any ideas are very welcome.

Is this a new development with a new dryer? If it is still under warranty, call the place where you got it. The cylinder may be tumbling too slowly to get the clothes to toss correctly. If it is an older dryer, it may be time for an upgrade.
A lot of stores (Sears, for example) will do service calls and some HVAC companies have appliance departments. Beware, though, you might have to pay a $90 or so service charge for them to come out and tell you that you need a new dryer.

I'm afraid i don't know if it's a new development. A friend gave it to me. It looks brand new. I asked this friend if he had any problems and he said no. But I'm afraid I wouldn't get a warranty since it's a gift. I think it's tumbling too fast. Is there any adjustment for this?

We had trouble with our dryer taking too long.. turns out we didn't have the dryer vent hose on correctly (it was too long and not venting correctly). Was still under warrantee and repairman fixed the problem. Works great now.

If there is a current warranty on the product it should still be valid even if you were not the original purchaser. You just need to have the paperwork, or call the store where the machine was purchased and see if they have the records.
I can't say if there is an adjustment for this because I don't know what settings your dryer has. You might be better off calling or going to an appliance store and describing your problem to people who sell them, or calling Maytag themselves and seeing what they have to say.
If the machine is new, it should still be under warranty -if there was a warranty to begin with.

Make sure you don't have it set on "air fluff" or "delicates" or anything, though.

You're drying too few items. Put more stuff in there, even if it's clean dry towels. Stuffs gotta have something to tumble with.

First of all, this is my advice to all my customers - DO NOT BUY MAYTAG WASHERS OR DRYERS.

They are awful and they have had numerous problems over the past 10 years that they have dealt with in various ways including one very large class action settlement. You can read a litany of complaints at consumer affairs website here: http://www.consumeraffairs.com/homeowners/maytag_wash.html (there are a ton of similar websites to this one with just as many negative reviews - this is how we found all the information about the class action suit for our customers... a simple google search puts all Maytag's dirty laundry out there for the world to see.)

Next - you live in Elk Grove Village and I happen to know that the people at Abt Electronics in Morton Grove are very helpful and inspite of the fact that you didn't purchase from them, they will likely help you if you ask. http://www.abt.com/custserv/abtCustServ.php3

Chicagoland 847.967.8830

They will at least give you an idea of how to approach your problem if you tell them a bit about it. I'm certain that they've dealt with Maytag washer problems because I've spent many hours dealing with them about it. They will likely be able to advise about dryer problems as well. Abt is a good family owned company - they may decide that it is good business sense to help you so you buy your next appliance from them - it has definitely had that effect on me.

Finally, you may want to talk to Maytag and tell them about your problem. They may agree to take a look at it for no cost because frankly, their company reputation has gone to complete hell. Anyone that remembers the old Maytag repairman ads will find it ironic that the company reputation has gone so incredibly bad lately.

So call people... you might find people willing to help. (and be suspicious that your friend unloaded a bad dryer on you.*)

*sorry for the puns... I swear they just happened.