you can download a manual from here
If you are getting loops in the thread underneath check your top tension, thread is probably not into the tension discs fully or at all. If you can get at them, clean between the tension discs, turn tension knob to zero, then "floss" between with the selvage edge of a clean piece of cotton fabric to remove any dye buildup or lint. Cheaper threads will shed fibres as they go through tension so best to avoid those bargain bin threads, fine for hand sewing but not so great on the machine long term. If you can't get at the tension discs then consider having a clean and service at least bi-annually to keep them clean as well as the other internal moving parts.
Uneven stitches can be caused by a blunt needle - you should put in a new one for each new sewing project (4-6 hours sewing time) ensuring it is a sharp for wovens or ball point for knits. There is a great guide to needles at http://sewing.about.com/od/sewingmachineindex/ig/Sewing-Machine-Needles/
Also review how you wind the bobbin, there needs to be tension onto the thread as it goes onto the bobbin, there might be a silver tension disc on top the thread goes around. Wind slowly, and apply a little pressure onto the top of the thread spool you are winding off - your scissors handle is good. This stops the spool bouncing around causing uneven tension on the thread. If the thread is stretched, then relaxed as it winds onto the bobbin, then it will go back to its normal position in the seam causing puckers.
Here's how I wind - take the thread from the spool across to the tension disc, then back to the bobbin, put thread tail through the hole on the bobbin and hold the tail. Pop bobbin onto bobbin winder spindle and click across to engage. Hold the tail and start winding (might be a button on your machine, or just the foot control), wind just enough to go across the bobbin core and hold the starting point. Stop and snip off the thread tail with your scissors. Restart winding slowly while putting some pressure onto the thread spool with your scissors curved handle into the top (I usually use Guttermann thread and they are tall spools coming up past the top of the pin, this might not apply if using a shorter spool but put some pressure onto it). Watch the thread going onto the bobbin and give it a nudge with your finger tip to ensure the thread fills top, middle and bottom of the core evenly, you don't want it all on the bottom or all in the middle.
Wind until 3/4 full, then stop, cut and remove from the spindle and return machine to normal sewing mode. If you have a mushroom type cap put it onto the thread spool now so the thread winds off smoothly as you sew. Also put a felt circle under your thread spool to assist smooth thread flow.
Also, have you cleaned in the rotary hook? You should brush this out each time you use the machine and refering to the manual, remove the bobbin holder/case and clean under it. All machines will get lint/thread bit build up in the rotary hook and need regular cleaning out to prevent impaired operation. Your machine probably also has a oiling wick under the holder, in a little depression in the middle. Don't touch it but you can give it a drop of good quality clear sewing machine oil every few months. Manufacturers would like you to give the machine to them annually for cleaning/lube etc but you can certainly do some cleaning regularly yourself to prolong machine life and keep it running smoothly.
Also, keep machine covered when not in use, never in full sunlight (plastic will yellow) and not in a damp area.
I hope that these tips help you a little, certainly if you try all the above and the machine still isn't performing as it should, then take it back to your dealer and ask them to test sew and confirm if it needs a service. A good dealer would do this for you ( I usually ring first so I don't get them at a busy time though). I have my machines serviced every two years and clean/oil myself each month in between.