Where to start
There's a lot to do and collect on Mara, and it can feel a little overwhelming at first, but it does all slowly click together the longer you are on the site. For me, one of the main things that drew me in were the collections, so this guide may be a bit biased towards those, but I think they all feed into the other site features nicely.
Earning MP is usually the main focus when you first start out, so in this first section I'll go over tips that got me to my first million mp pretty dang quick c:
Freebies
The site is full of free items and stats, so make sure you take advantage of them c:
On the bottom footer of the site, "Free Games" with the beachball icon will take you to a page with all of the free games that you can play on the site - this page contains both flash style games and random chance games - we'll focus on the random chance ones here and flash games can have their own section c:
There are a lot of random chance games with different timers - some you can play every couple of hours, whilst others are a once a day or even once every 48hrs, and if you have the notification bell on them ticked, they'll pop up in the right hand corner of your header banner whenever they are available. Some are more worthwhile than others, and there are some that I don't touch at all these days, but when you're first starting, try them all out and get as much MP as you can from them.
The games I personally rate the highest for payout are:
Ant Hill - the only way to get ant minipets, which are needed for the Tableus temple. Even if you are not interested in completing the temple, they sell for a lot!
Archeology - the only way to get keys, which are needed for the Transformation temple. Even if you are not interested in completing the temple, they sell for a lot!
Bingo
Clothing Rack - Free clothes! They are also often asked for by quests and sell for 10k+
Grave Robbing - Bones are good for toy collections, quests and making undying minipets, also sell for 10K+
Tombolas - Just a click and the rewards are the main items I delete to get deletion points
Fruit Machine - MP rewards of 10k, 25k and 50k, or you could win a capsule machine token too!
Guess the Flag - The shirts you win here are both good clothing collection items and sell for decent MP - even if you're no good at geography (like me, lol) you can just check the 'prize list' link on the game page to find the country name you're looking for, and it actually makes you start to remember world flags too, win-win!
Nutty Tree - Nuts are a gourmet food, usually sell for 50K+ or can be used to complete Knutt House quests - saving them up over the year can save you grief during events that require you to complete knutt house quests too!
Pot of Gold - Don't forget to donate good stuff to it sometimes too!
Prize drop - MP, stat and item prizes, usually 10k+ in worth
Test your Strength - One click and you can win up to 1 mil MP
Undying Fairy - One click and you can win up to 1 mil MP
Worm digging - You will either be in constant need for worms to complete Aquarium quests for scholarships, or if you don't care about uni stats, worms generally sell for 10k+ and sell quite quickly at that
Many thanks to LarcyleLayouts for the free layout, I suck at coding :'D
Good general site wide tips
Items
The symbols that you see next to some items mean that they are part of a collection! Here are their meanings:
Rubber duck = Toy collection
Crossed knife and fork = Gourmet food collection
Coat hanger = Clothing collection
Giftbox = Part of a collection that you can buy a giftbox to track
Think about saving your pearls! They are expensive due to Clam missions that need them and later requirements of Jenoa goals, needing you to have up to 175 unique pearls in your attic - a lot of these are retired or are one-per-account rewards so you may want to consider sticking any you get into your attic.
Similarily, be careful when using any other collection items (gourmet food, clothing, CDs, DVDs, books, instruments, photos) that you get from one-off rewards, like the site goals. As these are one-off and often needed for full collections or site goals, they tend to stay around the same price or increase.
It's generally a good idea to focus all items for a collection onto one pet, as you get better rewards the more items they have. Some people spread their collections around, so one pet is their gourmet pet, one their book pet, one for stats etc., but there are quite a few stat rewards for reaching certain collection levels, so I like to have everything going to one main pet personally (Cadvan is my everything pet, although Branston gets priority on gourmets for reasons, and everyone else is just here to look pretty :D )