So many blogs out there are far better then I will achieve here. Please take time to go through each one and learn more about what SL has to offer you.
General knowledge blogs:
SLforNowt or SLforNowt.com
This is a definate read for anyone starting out in Second Life. Along the top of the blog towards the right hand side you will see links for Inventory Management 101 and Newbie? Start here. I very highly suggest reading these guides.
Prim Lashes : You may not have prim lashes now but at some point you're going to come across them. Prim lashes are exactly that, lashes that are made of prims. When you first get them, they will not be sized to your avatar's eyes. You will have to move them to make them work. Click the link for the blog What the Fug?'s tutorial on Prim Lashes.
Delete Bling : A few years back, content makers added shining lights to items of clothing called Bling. For the most part this fell out of fashion. It's your own choice if you don't want to wear it and this tutorial from What the Fug's blog is a great way of getting rid of the script inside the item of clothing.
Tinting Prim Toes : Now this is an older post from What the Fug's blog but its still something you need to know. Shoes in Second Life usually come as just that, a shoe. But some have added fancy toes so that you can wear sandals or high heels with your little piggies hanging out.
(Don't forget if you have Viewer 2.0 that you have to turn on the color chooser. Hold down the CTRL, ALT, Q to bring up the Develop menu at the top of your screen. Click on the menu, go down to Show Info and then click Show Color Under Cursor. Click it again to turn it off)