If you're looking for symmetry worksheets that can be printed out from online you can go to www.superteacherworksheets.com. The sheets range from drawing lines of symmetry to determining correct lines of symmetry.
You can print off symmetry worksheets on these websites; www.superteacherworksheets.com/symmetry.html, www.tlsbooks.com/mathworksheets.htm and www.instantdisplay.co.uk/springpage.htm
Yes there are plenty of adjective worksheets online. Links to these are; www.schoolexpress.com/fws/cat.php?id=2286; havefunteaching.com/worksheets/...worksheets/adjective-worksheets
There are some great websites online such as MySchoolHouse.com that allow you to use online worksheets. You can also purchase textbooks full of worksheets.
You can find reading worksheets online at any reading comprehension website. The following is a great resource for any reading worksheets www.superteacherworksheets.com/comprehension.html.
This site offers antonyms worksheets for sale, http://havefunteaching.com/worksheets/english-worksheets/antonym-worksheets/. They offer worksheets for various grade levels both with and without pictures.
http://www.teach-nology.com/worksheets/graphic/neworg/pentagon.gif
You can find those onomatopoeia worksheets at odd ball reading dot com. They specialize in those rare but fun worksheets. You can use them online or print out.
www.schoolsparks.com/kindergarten-worksheets is a good place to find worksheets. There are some free worksheets available to download and there is also a workbook of worksheets available for purchase.
Pre-k worksheets can be found in many locations, both online and in print. Print worksheets could be found in your local library or in bookstores. I would recommend the sites education.com for online worksheets.
Lots of rounding numbers worksheets can be found online. Try Education.com for a good selection. Math.com is another great resource for math-related worksheets.
There are many free grammar worksheets online at grammaracy dot com. They offer the worksheets for free allowing you to download or save or print them while you are on their site.
First go to http://www.ereadingworksheets.com/free-reading-worksheets/reading-comprehension-worksheets/inferences-worksheets/. There you should find multiple links as to what you are looking for.