I just brought a Tasco 302911 114mm x 500mm reflector telescope from an op shop although it didn't come with any lenses. Where I can get lenses and which lenses do I buy?

The Tasco web site does not list that model-- however it is a small reflector style telescope similar to this model--

http://www.tasco.com/products/manuals/Luminova40-076420Inst.pdf

Use the above manual to help you assemble the scope.

No "use" books for Tasco telescopes. Find a local astronnomy club and the members will help you with the telescope.

It does not matter what it costs! Do not buy a Tasco telescope. Very poorly made, some even have plastic eyepieces and plastic lenses!

Check out this web site and others for a better, higher quality telescope.

http://www.telescope.com/control/main/

I would also suggest that you look at a Dobsonian mounted reflector like this one:

http://www.telescope.com/control/product/~category_id=classicdobs/~pcategory=dobsonians/~product_id=08942

First are you sure you have the CORRECT end of the scope pointed toward the sky? On a reflector type telescope that uses mirrors, the focuser is on the side of the tube on the UP end of the telescope. The mirror is in the bottom.

Mose caps simply pop off, others unscrew. You may be trying to remove the BOTTOM mirror!

You are NOT focused properly. Put the eyepiece with the largest number written on it into the focuser. DO NOT use the 2x barlow if you have one.

Go outside during the daytime and practice focusing on a distant object. Turn the focus knob back and forth slowly until the image is in sharp focus.

You will not find a manual for that small REFLECTOR style telescope. However the picture above-- that you show in your question shows the telescope mounted BACKWARDS actually pointed toward the ground!

Apparently FIXYA also does not know how to set up a reflector style telescope. The eyepiece and focuser end is on the UP end of the telescope with the mirror on the bottom end of the telescope.

Here is a manual for a MEADE brand telescope probably very similar to your telescope.

http://www.meade.com/manuals/TelescopeManuals/Reflectors/062002Jupiter114EQ-D.pdf

Read my TIPS on my profile page.

This is a small reflector style telescope. They all assemble the same way. I will give you a web link for a similar Meade brand scope that you can use to assemble your telescope.

Manual Link Meade Reflector:

http://www.meade.com/manuals/TelescopeManuals/Reflectors/062002Jupiter114EQ-D.pdf

Yes you can buy eyepieces at several retailers. Measure the hole. Eyepieces come in 3 different sizes: .965, 1.25 and 2 inch sizes.

Here are several retailers:

http://www.agenaastro.com/

http://shop.telescope-warehouse.com/category.sc?categoryId=2

I answered your question in your other posting.

SEE this and look at the picture of the Dobsonian reflector. Notice the eyepiece and focuser is on the FRONT of the telescope. The mirror is the BOTTOM of the telescope.
http://www.texasastro.org/telescope.php

You will not find a TASCO telescope. However Meade maintains a web site with all of their manuals. Look under REFRACTOR or REFLECTOR for one that is similar to your telescope. They all go together and work in a similar fashion.

http://www.meade.com/manuals/index.html
Meade manuals