baraka Allahu feeki, ya ukhti, my knowledge is less than a tiny pebble of a great bid mountain.
Here is what i found out, the best and solid way to learn tajweed is from a sheik or sheika. The latter might be in your best interest but online you probably will never find.
You should learn the rules first and before anything even before you learn from a sheik. That way the sheik will need to spend less time in the rules and more time with makraj and application. This will save you money if you are paying for it. Take your time and learn the rules and practice and pay attention to recitors like Mahmoud Al-Husary, Abdul-Basit or Mohamed Ayub. They nasalize the noon sakin very very good for the learner and there timing is as if they took a stop watch and where in tune with it. Don't worry about making your ghunna beutiful like you here Mishary and other in beginning, it will come naturally when you gain more experience and memorize more.
Here I will list some sites that I find a very good for tajweed(try and then stick to what you like):
First I read from a Quran with tajweed in color, similar to what I posted earlier but I have a hard copy as well, it looks like this:
http://www.quranflash.com/en/index.html#
CLICK ENTER TO VIEW
Second this is a starter course in knowing tajweed rules that I found really helpful(in audio is teaching):
http://www.tajweedinenglish.com/
IF YOU REGISTER YOU WILL HAVE MORE MATERIAL AND TIPS
Third there is a course here but I never can make the time for it but I like how they are organized and teach:
http://www.sunnahfollowers.net/index.php
Fourth, too much in the beginning will cause it to be overwhelming where you may not continue. So take your time later when you are stronger you will be able to memorize in tajweed a page or hizb. Everybody is unique in this, so never measure yourself to others besides yourself and where you where yesterday. Build success on success and never failure of attained what goals you set. Having said that start with even one Ayah. Here you will find a project that many websites use. All ayat are in individual mp3(pick what you want and who you want reciting; numbers are 000 for surah and 000 for ayah to make 000000.mp3):
http://www.versebyversequran.com/index.php?option=com_frontpage&Itemid=1&limit=4&limitstart=4
Fifth but start with this, is obtaining a well documented ebook of the rules of tajweed. Read it through and learn, at the same time you start to memorize in tajweed. But is better if you know about all the rules so that you can register in your mind the reason you madd or nasalize. here you can find ebook and cheat sheet(some links too):
http://www.understandquran.com/extras/tajweed.html
Finally we ask Allah subhanna wata3alla to make it easy for us to increase in that which will be better for us. And to increase us in knowledge which is beneficial. And to guide us to the fardous al-3alaa.
by the way, once you know the rules, than it is so easy and I use the color-coded Quran to make sure I don't miss anything. And according to a haafiz sheik, it is so much easier to memorize with tajweed than to have to go over and relearn.