Okay so, I'm not sure how helpful this will be, but I currently just remade my account and was way behind from my first account that I can no longer access...after 3 weeks, I have a bunch invested in the stock market and already have a full lab map, along with some saved up and working on the packrat avatar. Here's the list of things I did that have helped me to this point without using any cheats. Figured my first guide will be something to help out the people in my position, instead of thousands of the same "How can I get NP's?" threads being made.

Know your dailies!
You don't need to have them memorized, but find a good site that lists them and bookmark it (and I'm pretty sure there's a good one on this site, too!). (Don't forget the hidden nova in the advent calendar dailies, its a bonus item!) The Lunar Puzzle and Mysterious Negg Puzzle can easily be solved by simply googling the name of the puzzle. I'd post the sites I use to find the answers, but I'm pretty sure other guides from other sites are not allowed to be linked.

GAMES!
Learn what games will net you an easy 3k (1k per go) and favorite them to get easy access. Learn how many points are needed for that score, aim for it, and end game/send score. While some people suggest Score senders and other methods to get it done easily without playing, these are the games that I play legit to earn over 40k a day, which adds up.
My list is:
~ SPELLSEEKER - 100k points, end game, send score. Easiest way is shuffle beginning of level till gold pieces comes up and play on numbers mode. Can get 20-50k per level easy this way.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=1157
~ FASHION FEVER - Start game, End game, Send score X3 = 900NP
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=805
~AdverVideo - Goes quicker with Adblock installed. Watch video, spin wheel, rinse and repeat.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=1270
~Math's Nightmare - Set for Division, Potato Counter difficulty, and aim for 600 pts, end game, send score.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=885
~Magax II - Score 250 (mid lv 2), end game, send score
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=763
~Crisis Courier - Score 1850 (end of lv 2), end game, send score
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=773
~Cloud Racers - Score 360, quit, send score
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=1155
~Volcano Run II - Score 410 (mix of longest run plus bonus points, do math), end game, send score.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=761
~Nova Defender - Set difficulty to hard, Score 100k, end game, send score.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=1223
~Wrath of the Snowager - Score 100k, HIT A WALL FIRST, RESTART LEVEL, end game, send score. Ending without dying resets score.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=1269
~Assignment 53 - Can be more time consuming, but definitely easy. Score 3380, end game, send score. ~3rd level or so is enough for points.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=1347
~Kass Basher - Play until you unlock hard difficulty (Bat), then score 850+ and send score. Trick is hit the kass at 9 wind, hold the mouse or spacebar until the kass hits the peak, then let it glide down. Hitting mouse or space as it hits the ground causes a bounce, allowing extra distance.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=381
~Catch the Petpet - Always get a full 700, easy game. I'd restart if you mis-clicked.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=1034
~Big Time Rush - Can get an easy 620 NP per play by clicking the only characters w/ a real picture.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=1245
~Smug Bug Smite - Easy 3 level shoot-bug-as-they-appear game, nets about 500 a game.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=933
~Chariot Chase - Takes about 5 laps to get the 820 necessary for the full score.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=1148
~Mop n' Bop - Score 1550, end game, send score. When a full lap is completed, (icon on top bar has yellow border) you can upgrade your mop/mop head for more points.
HTML Code:
http://www.neopets.com/games/game.phtml?game_id=904
Restocking!
"But I don't know how to restock!" Well, try and learn. You might end up losing some money, but at least you learn patterns. Find out what sells, find out what NST time prices fluctuate or stay the same the most, and find out what really sells! Main items that sell are one use items, such as some battledome weapons, potions, and stat-raising items (Dubloons and codestones). Another way to do this is by checking out actual shops. Depending on the age of your account, I recently discovered that older accounts see higher rarity items restocked in the NPC shops, so I've been using the Igloo Garage Sale (
HTML Code:
http://www.neopets.com/winter/igloo.phtml
) which sells items cheaply that can flip for a profit, while the demand might not be too great for the item. Other methods are using the shop wizard, repeatedly searching an item, and find someone who puts it under a bit too low.

HABITARIUM!
While the profit may not be too significant, it adds up. You get a scaling increase in neopoints per level that you get, up to 50. There is a great guide on here, written by Trinket and located at
HTML Code:
http://clraik.com/forum/showthread.php?3219-%E2%98%85-Guide-Habitarium-Level-50-the-Fastest-Method
. While I did say that I did not cheat, This is the one exception I can admit. On my time not playing, I'd run Habibot in the background. Habibot is located at
HTML Code:
http://clraik.com/forum/showthread.php?19399-Habi-Bot-1-1-User-Guide
and contains the information needed to run it. Lets say you have to leave for an hour or two...why not just turn the bot on and let it manage your Petpetpet's health and gathering, while helping you get levels? Feel free to ask me questions, as I had some trouble setting it up initially, until I received some help! And the best part? Once you hit level 50, you can get purple gems that add 500 NP's directly to your account, which come fairly frequent!

Battledome!
It is definitely worth it to at least raise the stats on one pet. Even if you repeatedly versus the same 10 difficulty opponent, you can still win a maximum of 15 items a day, including codestones, which can sell for a couple of thousand. It adds up!

Stock Market
Located at
HTML Code:
http://www.neopets.com/stockmarket.phtml
. While people say (and I've seen) long term success with this, my numbers have not proven as profitable. Basically, the rule of thumb is buy shares at 15 NP x 1000, sell when they hit 30 NP a share. Some people say they have seen shares raise over 70 each, which is a flip from 15k to 70k. Either way, there is close to no harm in investing, unless a stock goes bankrupt which does not happen too often from what I've seen. Mostly, it's a game of patience that will yield profit, rather than just dumping it in the bank.


The End
I hope my first guide might help some people get an idea of what can be done. While I am well aware that there are several other guides out there for newbies, none of them seemed to relay all the information the way I've gotten it. Hope this meets clraik standard Please leave comments and questions underneath and I'll do my best to answer them (or at least lead you in the right direction if I can)!